2001 OKLAHOMA CITY, OKLAHOMA (OKC)

Oklahoma City is located along the North Canadian River, a frequently nearly–dry stream, at the geographic center of the state. It is not quite 1,000 miles south of the Canadian Border and a little less than 500 miles north of the Gulf of Mexico. The surrounding country is gently rolling with the nearest hills or low mountains, the Arbuckles, 80 miles south. The elevation ranges around 1,250 feet above sea level.

Although some influence is exerted at times by warm, moist air currents from the Gulf of Mexico, the climate of Oklahoma City falls mainly under continental controls characteristic of the Great Plains Region. The continental effect produces pronounced daily and seasonal temperature changes and considerable variation in seasonal and annual precipitation. Summers are long and usually hot. Winters are comparatively mild and short.

During the year, temperatures of 100 degrees or more occur on an average of 10 days, but have occurred on as many as 50 days or more. While summers are usually hot, the discomforting effect of extreme heat is considerably mitigated by low humidity and the prevalence of a moderate southerly breeze. Approximately one winter in three has temperatures of zero or lower.

The length of the growing season varies from 180 to 251 days. Average date of last freeze is early April and average date of first freeze is early November. Freezes have occurred in early October.

During an average year, skies are clear approximately 40 percent of the time, partly cloudy 25 percent, and cloudy 35 percent of the time. The city is almost smoke–free as a result of favorable atmospheric conditions and the almost exclusive use of natural gas for heating. Flying conditions are generally very good with flight by visual flight rules possible about 96 percent of the time.

Summer rainfall comes mainly from showers and thunderstorms. Winter precipitation is generally associated with frontal passages. Measurable precipitation has occurred on as many as 122 days and as few as 55 days during the year. The seasonal distribution of precipitation is normally 12 percent in winter, 34 percent in spring, 30 percent in summer, and 24 percent in fall. The The period with the least number of days with precipitation is November through January, and the month with the most rainy days is May. Thunderstorms occur most often in late spring and early summer. Large hail and/or destructive winds on occasion accompany these thunderstorms.

Snowfall averages less than 10 inches per year and seldom remains on the ground very long. Occasional brief periods of freezing rain and sleet storms occur.

Heavy fogs are infrequent. Prevailing winds are southerly except in January and February when northerly breezes predominate.

NORMALS, MEANS, AND EXTREMES

OKLAHOMA CITY, OK (OKC)

LATITUDE:    LONGITUDE:     ELEVATION (FT):    TIME ZONE:    WBAN: 13967

35 23′ 19″ N  97 36′ 01″ W  GRND:  1281  BARO: &#x 0A0;1284  CENTRAL (UTC + 6)

	ELEMENT	POR	JAN	FEB	MAR	APR	MAY	JUN	JUL	AUG	SEP	OCT	NOV	DEC	YEAR
TEMPERATURE F	NORMAL DAILY MAXIMUM	30	46.7	52.1	62.0	71.9	79.1	87.3	93.4	92.5	83.8	73.6	60.4	49.9	71.1
	MEAN DAILY MAXIMUM	62	46.9	52.7	61.3	71.5	79.1	87.3	93.1	92.7	84.4	74.1	59.8	50.3	71.1
	HIGHEST DAILY MAXIMUM	47	80	92	93	100	104	105	110	110	108	96	87	86	110
	YEAR OF OCCURRENCE		1986	1996	1967	1972	1985	1998	1996	1980	2000	1972	1980	1955	JUL 1996
	MEAN OF EXTREME MAXS.	53	69.2	74.9	82.2	87.5	91.6	96.8	101.4	101.4	96.8	89.1	77.6	70.5	86.6
	NORMAL DAILY MINIMUM	30	25.2	29.6	38.5	48.8	57.7	66.1	70.6	69.6	62.2	50.4	38.6	28.6	48.8
	MEAN DAILY MINIMUM	62	26.4	30.8	38.0	48.8	58.0	66.7	70.8	69.8	62.0	51.1	38.2	29.6	49.2
	LOWEST DAILY MINIMUM	47	-4	-3	3	20	37	47	53	51	36	16	11	-8	-8
	YEAR OF OCCURRENCE		1988	1996	1960	1957	1981	1954	1971	1956	1989	1993	1991	1989	DEC 1989
	MEAN OF EXTREME MINS.	53	7.7	12.9	20.2	32.3	44.6	55.6	62.4	60.3	46.4	33.9	21.8	12.3	34.2
	NORMAL DRY BULB	30	35.9	40.9	50.3	60.4	68.4	76.7	82.0	81.1	73.0	62.0	49.6	39.3	60.0
	MEAN DRY BULB	62	36.8	41.8	49.7	60.2	68.6	77.1	82.0	81.4	73.2	62.6	49.1	39.9	60.2
	MEAN WET BULB	59	32.2	36.5	43.0	52.4	61.3	68.5	71.1	69.8	64.1	54.6	43.0	35.2	52.6
	MEAN DEW POINT	59	25.9	29.7	35.5	45.8	57.0	64.8	66.3	65.0	59.2	48.6	36.8	28.9	47.0
	NORMAL NO. DAYS WITH:
	MAXIMUM 90	30	0.0	0.0	0.1	0.5	2.2	12.0	22.4	22.4	8.8	1.2	0.0	0.0	69.6
	MAXIMUM 32	30	5.2	2.4	0.2	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.1	2.9	10.8
	MINIMUM 32	30	23.1	17.0	8.4	0.9	0.0	0.0	0.0	0.0	0.0	0.4	7.9	20.0	77.7
	MINIMUM 0	30	0.5	0.1	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.2	0.8
H/C	NORMAL HEATING DEG. DAYS	30	902	675	464	176	31	0	0	0	15	137	462	797	3659
	NORMAL COOLING DEG. DAYS	30	0	0	9	38	136	351	527	499	255	44	0	0	1859
RH	NORMAL (PERCENT)	30	67	66	61	61	68	67	61	62	67	64	67	68	65
	HOUR 00 LST	30	72	72	68	69	76	77	70	70	76	72	74	73	72
	HOUR 06 LST	30	77	77	75	76	83	84	80	80	83	79	79	78	79
	HOUR 12 LST	30	58	58	52	51	57	56	49	50	55	52	56	58	54
	HOUR 18 LST	30	58	54	48	48	54	53	46	46	53	54	60	62	53
S	PERCENT POSSIBLE SUNSHINE	41	60	61	65	66	66	76	80	80	74	70	62	59	68
W/O	MEAN NO. DAYS WITH:
	HEAVY FOG(VISBY 1/4 MI)	52	3.8	3.3	1.8	1.0	0.8	0.5	0.3	0.5	0.8	1.6	2.1	3.3	19.8
	THUNDERSTORMS	61	0.5	1.4	3.3	5.5	8.8	8.7	6.0	6.3	5.1	3.4	1.3	0.7	51.0
CLOUDINESS	MEAN:
	SUNRISE-SUNSET (OKTAS)	2	4.8	5.1	5.3	4.8	5.2	2.4	2.0	2.7	4.8	3.6	3.2	4.8	4.1
	MIDNIGHT-MIDNIGHT (OKTAS)	1	4.8	5.2	5.1	4.8	5.2	2.4	2.0	2.4	2.4	3.2	3.6	4.0	3.8
	MEAN NO. DAYS WITH:
	CLEAR	2	4.3	10.0	8.3	10.5	8.7	13.0	16.0	15.0	7.0	12.5	5.5	8.5	119.3
	PARTLY CLOUDY	2	4.7	2.7	2.7	2.0	6.0	5.3	4.5	4.5	3.0	4.0	4.5	5.0	48.9
	CLOUDY	2	7.3	10.0	7.0	8.0	6.3	3.3	2.5	3.0	2.0	5.0	6.5	7.5	68.4
PR	MEAN STATION PRESSURE(IN)	28	28.73	28.69	28.59	28.58	28.55	28.58	28.63	28.64	28.66	28.69	28.68	28.73	28.65
	MEAN SEA-LEVEL PRES. (IN)	59	30.15	30.09	29.98	29.94	29.92	29.90	29.96	29.97	30.00	30.04	30.07	30.12	30.01
WINDS	MEAN SPEED (MPH)	40	13.1	13.8	14.9	14.6	13.1	12.4	11.4	10.6	11.5	12.3	12.9	12.8	12.8
	PREVAIL. DIR (TENS OF DEGS)	21	36	36	16	16	16	16	16	16	16	16	16	36	16
	MAXIMUM 2-MINUTE:
	SPEED (MPH)	8	45	45	52	46	47	41	48	46	38	43	46	44	52
	DIR. (TENS OF DEGS)		34	32	24	32	01	25	34	05	33	03	19	33	24
	YEAR OF OCCURRENCE		1996	1997	1996	1999	2001	1993	2000	1996	1998	1994	1994	2000	MAR 1996
	MAXIMUM 5-SECOND:
	SPEED (MPH)	8	53	54	62	55	63	63	64	52	48	51	56	52	64
	DIR. (TENS OF DEGS)		33	33	23	32	01	22	33	05	29	03	20	33	33
	YEAR OF OCCURRENCE		1996	1997	1996	1999	2001	1998	2000	1996	1998	1994	1994	2000	JUL 2000
PRECIPITATION	NORMAL (IN)	30	1.13	1.56	2.71	2.77	5.22	4.31	2.61	2.60	3.84	3.23	1.98	1.40	33.36
	MAXIMUM MONTHLY (IN)	61	5.68	4.63	7.85	10.78	12.07	14.66	11.90	6.77	11.85	13.18	5.72	8.14	14.66
	YEAR OF OCCURRENCE		1949	1990	1988	1947	1982	1989	1996	1966	1991	1983	1994	1984	JUN 1989
	MINIMUM MONTHLY (IN)	61	0.00	T	T	0.17	0.33	0.55	T	0.00	T	T	T	0.03	0.00
	YEAR OF OCCURRENCE		1985	1947	1940	1989	1942	2001	1983	2000	1948	1958	1949	1996	AUG 2000
	MAXIMUM IN 24 HOURS (IN)	61	3.10	2.21	3.44	4.48	7.56	4.56	5.75	3.56	7.68	8.95	2.89	2.89	8.95
	YEAR OF OCCURRENCE		1982	1978	1944	1999	1993	1989	1981	1989	1970	1983	1994	1991	OCT 1983
	NORMAL NO. DAYS WITH:
	PRECIPITATION 0.01	30	5.1	6.1	7.2	7.4	9.6	8.1	6.1	6.7	7.7	6.5	5.7	5.6	81.8
	PRECIPITATION 1.00	30	0.3	0.3	0.8	0.8	1.5	1.4	0.7	0.9	1.1	0.9	0.6	0.4	9.7
SNOWFALL	NORMAL (IN)	30	2.8	2.7	1.2	0.*	0.0	0.0	0.0	0.0	0.0	0.0	0.6	1.8	9.1
	MAXIMUM MONTHLY (IN)	61	17.3	12.0	13.9	0.7	T	T	T	T	T	0.1	7.5	8.3	17.3
	YEAR OF OCCURRENCE		1949	1978	1968	1957	1992	1992	1997	1997	1992	1993	1972	1987	JAN 1949
	MAXIMUM IN 24 HOURS (IN)	61	8.9	6.5	8.4	0.7	T	T	T	T	T	0.1	5.5	8.3	8.9
	YEAR OF OCCURRENCE		1988	1986	1948	1957	1992	1992	1997	1997	1992	1993	1972	1987	JAN 1988
	MAXIMUM SNOW DEPTH (IN)	53	12	8	8	T	0	0	0	0	0	T	3	7	12
	YEAR OF OCCURRENCE		1988	1951	1948	1973						1993	1980	1987	JAN 1988
	NORMAL NO. DAYS WITH:
	SNOWFALL 1.0	30	0.9	1.1	0.3	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.2	0.6	3.1

PRECIPITATION (inches) 2001 OKLAHOMA CITY, OK (OKC)
YEAR	JAN	FEB	MAR	APR	MAY	JUN	JUL	AUG	SEP	OCT	NOV	DEC	ANNUAL
1972	0.21	0.43	1.13	3.10	4.03	1.36	3.22	1.82	2.04	7.17	2.28	0.84	27.63
1973	3.39	0.31	6.76	2.32	3.61	6.31	3.38	1.36	8.00	3.05	2.81	0.47	41.77
1974	0.10	2.68	3.12	4.66	5.01	3.36	0.48	4.42	6.24	5.57	2.34	1.47	39.45
1975	1.99	1.90	1.72	1.92	8.76	4.82	7.71	0.60	1.92	0.84	1.77	1.30	35.25
1976	T	0.33	3.09	2.94	4.36	0.88	1.38	1.46	1.53	1.78	0.12	0.19	18.06
1977	0.32	1.40	1.30	2.88	7.97	2.00	4.10	3.08	1.20	2.41	1.59	0.34	28.59
1978	1.26	3.23	1.32	1.65	10.12	4.04	3.75	0.25	0.96	1.02	2.88	0.70	31.18
1979	1.55	0.63	2.73	2.78	7.29	9.94	5.62	3.78	0.72	1.58	1.93	2.57	41.12
1980	1.69	1.29	1.38	2.16	9.00	2.52	0.42	0.60	2.21	0.99	0.51	1.58	24.35
1981	0.19	1.15	2.87	2.97	2.73	7.49	6.45	3.61	1.48	7.70	2.11	0.20	38.95
1982	3.68	0.98	1.63	1.92	12.07	4.06	2.11	1.13	2.86	1.03	2.78	1.94	36.19
1983	2.62	1.71	2.51	2.34	6.88	3.18	T	3.18	0.90	13.18	1.90	0.70	39.10
1984	0.35	1.16	4.70	1.79	1.62	3.48	0.30	2.35	1.01	6.64	2.05	8.14	33.59
1985	0.92	3.71	6.60	5.35	1.49	8.34	1.33	2.63	4.59	5.23	3.73	0.26	44.18
1986	0.00	0.68	1.75	4.42	8.21	3.11	0.38	3.29	9.54	8.00	4.63	1.16	45.17
1987	2.45	4.05	2.33	0.41	11.86	6.50	2.99	1.83	4.58	1.82	1.92	3.75	44.49
1988	1.24	0.41	7.85	3.19	1.07	3.59	1.92	1.60	5.19	2.04	2.45	1.39	31.94
1989	1.17	2.20	2.72	0.17	4.33	14.66	1.91	5.55	4.51	3.26	0.09	0.32	40.89
1990	1.85	4.63	4.43	5.11	5.79	1.25	2.65	3.16	7.35	1.27	1.59	1.46	40.54
1991	0.89	0.03	1.59	2.10	6.39	3.85	1.98	3.24	11.85	3.98	1.94	5.90	43.74
1992	1.15	1.28	1.08	3.64	4.88	6.35	4.01	5.82	2.92	1.13	4.51	3.08	39.85
1993	1.90	3.21	2.82	2.50	10.90	2.65	1.24	1.86	7.05	0.47	1.34	1.27	37.21
1994	0.21	2.56	3.18	3.38	2.69	1.70	2.17	1.81	2.17	1.88	5.72	1.63	29.10
1995	1.28	0.04	2.21	3.76	7.39	6.06	1.94	3.15	6.66	1.54	0.39	2.35	36.77
1996	0.08	0.02	2.17	2.00	1.90	1.16	11.90	5.85	5.88	2.53	3.36	T	36.85
1997	0.52	2.59	0.60	4.39	3.68	3.01	4.60	4.04	1.66	3.93	1.11	2.96	33.09
1998	4.09	0.32	6.45	3.34	2.12	2.67	0.02	0.48	4.39	6.76	3.09	1.62	35.35
1999	1.81	1.20	3.45	6.92	3.10	8.61	1.94	1.35	4.88	2.22	0.06	3.71	39.25
2000	0.75	1.47	3.12	5.17	1.36	6.71	5.25	0.00	1.73	8.39	2.79	2.30	39.04
2001	2.23	2.25	1.01	1.04	7.70	0.55	1.27	1.95	5.55	3.56	1.08	0.91	29.10
POR=63 YRS	1.24	1.49	2.40	3.13	5.27	4.31	2.80	2.54	3.70	3.03	1.79	1.53	33.23

AVERAGE TEMPERATURE (F) 2001 OKLAHOMA CITY, OK (OKC)
YEAR	JAN	FEB	MAR	APR	MAY	JUN	JUL	AUG	SEP	OCT	NOV	DEC	ANNUAL
1972	34.9	42.1	53.4	63.2	67.6	79.0	79.8	80.4	75.8	61.1	43.4	34.4	59.6
1973	33.3	39.8	52.5	56.0	66.8	75.2	79.8	79.7	70.6	64.3	53.1	39.3	59.2
1974	35.0	44.4	54.8	60.0	71.5	74.1	82.7	78.5	65.5	63.5	49.3	39.6	59.9
1975	40.3	36.5	46.1	58.7	67.4	75.1	78.0	80.1	68.3	63.4	50.7	41.8	58.9
1976	39.0	52.2	52.4	61.6	63.6	74.8	79.8	81.3	72.6	56.5	43.9	38.8	59.7
1977	29.2	45.9	54.1	62.5	70.0	79.6	83.0	80.7	78.0	62.7	50.9	40.0	61.4
1978	26.3	29.4	49.1	64.5	68.1	77.3	87.0	82.6	79.7	64.7	50.4	36.9	59.7
1979	25.4	31.5	51.2	58.1	65.8	75.2	81.0	80.0	73.1	65.7	46.5	43.3	58.1
1980	38.2	38.2	46.3	56.7	69.0	81.4	88.3	88.0	76.3	61.1	50.3	41.9	61.3
1981	37.7	43.9	51.9	65.6	65.7	78.4	84.2	78.8	74.1	60.1	50.3	39.1	60.8
1982	35.3	37.7	52.7	57.5	68.2	72.2	81.0	84.1	74.5	62.7	48.6	43.2	59.8
1983	38.6	42.6	48.8	54.0	64.6	73.4	81.6	84.0	74.9	62.7	50.4	25.8	58.5
1984	34.0	45.4	46.4	56.5	68.4	78.6	81.6	82.6	71.5	61.6	49.7	43.0	59.9
1985	30.6	37.2	53.0	62.7	70.0	76.0	80.9	81.3	73.1	61.2	46.1	35.1	58.9
1986	43.6	44.8	55.5	62.8	69.0	79.0	85.9	80.0	74.8	61.6	44.8	40.8	61.9
1987	35.1	45.9	50.3	61.8	72.6	77.1	80.1	82.2	72.4	60.0	50.5	40.6	60.7
1988	34.2	40.3	49.5	58.9	70.3	78.4	81.6	82.8	73.5	59.3	51.2	43.9	60.3
1989	42.8	33.1	51.1	63.4	69.4	74.3	79.6	78.3	67.8	63.1	52.2	32.7	59.0
1990	45.9	46.0	52.6	59.2	68.6	82.0	80.7	81.6	77.0	60.9	54.9	37.1	62.2
1991	34.9	49.0	54.3	62.5	72.3	78.0	82.2	81.2	70.9	62.6	45.0	44.1	61.4
1992	42.0	49.9	54.1	61.3	66.5	74.1	81.1	74.8	72.5	62.3	45.9	39.8	60.4
1993	36.5	38.8	48.0	56.2	66.0	76.8	83.6	82.3	69.8	57.1	44.2	42.0	58.4
1994	36.0	37.4	52.7	59.4	66.8	79.6	79.9	79.7	70.7	62.6	50.1	42.5	59.8
1995	38.6	44.9	49.8	56.8	64.3	73.0	81.0	81.5	70.9	61.6	49.3	39.9	59.3
1996	35.8	44.3	46.0	58.7	73.8	77.9	81.3	78.0	69.4	61.2	46.3	42.3	59.6
1997	37.8	44.0	52.5	54.7	66.7	75.4	81.6	78.6	75.3	62.3	46.5	39.1	59.5
1998	40.6	45.5	47.4	57.4	72.5	81.1	88.0	85.0	81.2	64.4	53.2	41.6	63.2
1999	40.5	50.7	49.8	61.3	68.1	75.7	82.2	84.8	71.1	62.7	56.8	43.3	62.3
2000	40.7	49.1	53.4	59.0	71.0	74.6	80.8	85.4	76.1	64.1	43.3	30.5	60.7
2001	36.3	40.8	46.6	63.6	69.5	76.4	85.7	82.9	70.7	60.2	53.9	42.2	60.7
POR=63 YRS	36.8	41.9	49.9	60.1	68.5	76.9	82.0	81.4	73.3	62.6	49.1	39.9	60.2

REFERENCE NOTES:

PAGE 1:

THE TEMPERATURE GRAPH SHOWS NORMAL MAXIMUM AND NORMAL MINIMUM DAILY TEMPERATURES (SOLID CURVES) AND THE ACTUAL DAILY HIGH AND LOW TEMPERATURES (VERTICAL BARS).

PAGE 2 AND 3:

H/C INDICATES HEATING AND COOLING DEGREE DAYS.

RH INDICATES RELATIVE HUMIDITY

W/O INDICATES WEATHER AND OBSTRUCTIONS

S INDICATES SUNSHINE.

PR INDICATES PRESSURE.

CLOUDINESS ON PAGE 3 IS THE SUM OF THE CEILOMETER AND SATELLITE DATA NOT TO EXCEED EIGHT EIGHTHS (OKTAS).

GENERAL:

T INDICATES TRACE PRECIPITATION, AN AMOUNT GREATER THAN ZERO BUT LESS THAN THE LOWEST REPORTABLE VALUE.

+ INDICATES THE VALUE ALSO OCCURS ON EARLIER DATES.

BLANK ENTRIES DENOTE MISSING OR UNREPORTED DATA.

NORMALS ARE 30–YEAR AVERAGES (1961–1990).

ASOS INDICATES AUTOMATED SURFACE OBSERVING SYSTEM.

PM INDICATES THE LAST DAY OF THE PREVIOUS MONTH.

POR (PERIOD OF RECORD) BEGINS WITH THE JANUARY DATA MONTH AND IS THE NUMBER OF YEARS USED TO COMPUTE THE MEAN. INDIVIDUAL MONTHS WITHIN THE POR MAY BE MISSING.

WHEN THE POR FOR A NORMAL IS LESS THAN 30 YEARS, THE NORMAL IS PROVISIONAL AND IS BASED ON THE NUMBER OF YEARS INDICATED.

0.* OR * INDICATES THE VALUE OR MEAN–DAYS–WITH IS BETWEEN 0.00 AND 0.05.

CLOUDINESS FOR ASOS STATIONS DIFFERS FROM THE NON–ASOS OBSERVATION TAKEN BY A HUMAN OBSERVER. ASOS STATION CLOUDINESS IS BASED ON TIME–AVERAGED CEILOMETER DATA FOR CLOUDS AT OR BELOW 12,000 FEET AND ON SATELLITE DATA FOR CLOUDS ABOVE 12,000 FEET.

THE NUMBER OF DAYS WITH CLEAR, PARTLY CLOUDY, AND CLOUDY CONDITIONS FOR ASOS STATIONS IS THE SUM OF THE CEILOMETER AND SATELLITE DATA FOR THE SUNRISE TO SUNSET PERIOD.

GENERAL CONTINUED:

CLEAR INDICATES 0–2 OKTAS, PARTLY CLOUDY INDICATES 3–6 OKTAS, AND CLOUDY INDICATES 7 OR 8 OKTAS. WHEN AT LEAST ONE OF THE ELEMENTS (CEILOMETER OR SATELLITE) IS MISSING, THE DAILY CLOUDINESS IS NOT COMPUTED.

WIND DIRECTION IS RECORDED IN TENS OF DEGREES (2 DIGITS) CLOCKWISE FROM TRUE NORTH. "00" INDICATES CALM. "36" INDICATES TRUE NORTH.

RESULTANT WIND IS THE VECTOR AVERAGE OF THE SPEED AND DIRECTION.

AVERAGE TEMPERATURE IS THE SUM OF THE MEAN DAILY MAXIMUM AND MINIMUM TEMPERATURE DIVIDED BY 2.

SNOWFALL DATA COMPRISE ALL FORMS OF FROZEN PRECIPITATION, INCLUDING HAIL.

A HEATING (COOLING) DEGREE DAY IS THE DIFFERENCE BETWEEN THE AVERAGE DAILY TEMPERATURE AND 65 F.

DRY BULB IS THE TEMPERATURE OF THE AMBIENT AIR.

DEW POINT IS THE TEMPERATURE TO WHICH THE AIR MUST BE COOLED TO ACHIEVE 100 PERCENT RELATIVE HUMIDITY.

WET BULB IS THE TEMPERATURE THE AIR WOULD HAVE IF THE MOISTURE CONTENT WAS INCREASED TO 100 PERCENT RELATIVE HUMIDITY.

ON JULY 1, 1996, THE NATIONAL WEATHER SERVICE BEGAN USING THE "METAR" OBSERVATION CODE THAT WAS ALREADY EMPLOYED BY MOST OTHER NATIONS OF THE WORLD. THE MOST NOTICEABLE DIFFERENCE IN THIS ANNUAL PUBLICATION WILL BE THE CHANGE IN UNITS FROM TENTHS TO EIGHTS (OKTAS) FOR REPORTING THE AMOUNT OF SKY COVER.

HEATING DEGREE DAYS (base 65 F) 2001 OKLAHOMA CITY, OK (OKC)
YEAR	JUL	AUG	SEP	OCT	NOV	DEC	JAN	FEB	MAR	APR	MAY	JUN	TOTAL
1972-73	0	0	23	225	640	940	975	701	380	283	55	0	4222
1973-74	0	0	37	99	362	787	922	573	330	168	8	0	3286
1974-75	0	0	56	88	463	784	763	792	583	235	29	0	3793
1975-76	0	0	64	126	430	713	801	367	406	128	100	0	3135
1976-77	0	0	19	306	629	805	1103	529	338	107	7	0	3843
1977-78	0	0	0	115	420	766	1192	990	493	90	64	0	4130
1978-79	0	0	2	89	437	866	1221	932	434	217	81	0	4279
1979-80	0	0	2	92	551	669	823	771	572	249	24	0	3753
1980-81	0	0	23	180	444	710	839	587	400	69	69	0	3321
1981-82	0	0	22	189	434	797	913	759	382	248	25	13	3782
1982-83	0	0	14	156	490	671	809	622	496	345	96	9	3708
1983-84	0	0	25	117	439	1207	955	561	572	263	45	0	4184
1984-85	0	0	75	162	462	676	1059	773	377	108	10	0	3702
1985-86	0	0	63	146	562	921	656	562	308	122	17	0	3357
1986-87	0	0	2	137	599	742	918	528	450	177	3	0	3556
1987-88	0	0	1	165	442	748	948	712	473	204	14	0	3707
1988-89	0	0	8	196	408	644	679	887	441	140	38	0	3441
1989-90	0	0	78	135	386	993	583	525	387	202	52	0	3341
1990-91	0	0	9	169	307	860	925	444	339	110	25	0	3188
1991-92	0	0	37	150	594	642	704	430	332	154	59	2	3104
1992-93	0	1	5	115	563	774	878	725	525	265	53	0	3904
1993-94	0	1	27	269	619	706	896	767	394	204	53	0	3936
1994-95	0	0	31	138	451	690	810	554	477	253	84	0	3488
1995-96	0	0	75	129	465	767	898	602	584	209	10	0	3739
1996-97	0	0	29	151	556	697	839	583	385	310	43	0	3593
1997-98	0	1	2	188	549	798	750	542	554	238	9	3	3634
1998-99	0	0	0	75	347	719	752	398	463	144	28	0	2926
1999-00	0	0	34	115	249	669	746	457	354	192	40	1	2857
2000-01	0	0	35	113	648	1063	882	672	561	105	22	0	4101
2001-	0	0	18	169	338	698

COOLING DEGREE DAYS (base 65 F) 2001 OKLAHOMA CITY, OK (OKC)
YEAR	JAN	FEB	MAR	APR	MAY	JUN	JUL	AUG	SEP	OCT	NOV	DEC	ANNUAL
1972	0	2	11	97	133	429	470	483	351	109	0	0	2085
1973	0	0	0	19	119	312	465	462	216	83	11	0	1687
1974	0	0	22	26	217	280	553	426	80	47	0	0	1651
1975	0	0	1	53	108	310	410	476	170	83	4	0	1615
1976	0	1	23	33	62	300	468	512	253	50	0	0	1702
1977	0	1	8	37	170	445	565	491	395	49	2	0	2163
1978	0	0	8	80	165	378	690	553	450	87	7	0	2418
1979	0	0	10	18	112	314	505	471	252	121	2	0	1805
1980	0	0	0	7	155	498	729	721	366	65	11	2	2554
1981	0	4	0	94	98	409	603	435	304	47	0	0	1994
1982	0	0	9	28	130	234	503	598	305	90	3	1	1901
1983	0	0	0	20	91	266	523	599	329	54	8	0	1890
1984	0	0	0	16	159	414	521	551	279	64	5	0	2009
1985	0	0	12	43	172	336	501	512	313	38	0	0	1927
1986	0	2	21	63	147	425	653	473	301	40	0	0	2125
1987	0	0	0	88	242	371	475	543	230	18	12	0	1979
1988	0	0	1	29	186	410	525	558	270	25	1	0	2005
1989	0	0	16	100	179	285	459	419	170	83	8	0	1719
1990	0	0	12	33	169	517	495	522	378	48	13	0	2187
1991	0	0	15	45	257	398	542	507	219	85	1	0	2069
1992	0	0	3	51	114	283	508	312	239	36	0	1	1547
1993	0	0	4	9	89	362	584	545	177	32	0	0	1802
1994	0	0	20	44	116	446	470	464	208	70	9	0	1847
1995	0	0	11	14	72	250	506	521	262	33	0	0	1669
1996	0	7	4	28	288	382	514	408	170	42	0	0	1843
1997	2	0	5	7	104	316	520	429	317	112	0	0	1812
1998	0	0	13	16	252	496	719	627	497	62	2	0	2684
1999	0	4	0	40	131	327	540	619	225	51	10	0	1947
2000	0	0	3	20	232	295	498	639	372	94	0	0	2153
2001	0	0	0	70	168	348	650	563	196	27	8	1	2031

SNOWFALL (inches) 2001 OKLAHOMA CITY, OK (OKC)
YEAR	JUL	AUG	SEP	OCT	NOV	DEC	JAN	FEB	MAR	APR	MAY	JUN	TOTAL
1972-73	0.0	0.0	0.0	0.0	7.5	1.4	8.3	0.2	T	T	0.0	0.0	17.4
1973-74	0.0	0.0	0.0	0.0	0.0	0.6	0.7	1.0	0.5	0.0	0.0	0.0	2.8
1974-75	0.0	0.0	0.0	0.0	1.0	2.0	0.6	0.9	0.1	0.0	0.0	0.0	4.6
1975-76	0.0	0.0	0.0	0.0	0.7	3.9	T	0.3	0.0	0.0	0.0	0.0	4.9
1976-77	0.0	0.0	0.0	0.0	0.3	T	2.8	0.4	0.0	0.0	0.0	0.0	3.5
1977-78	0.0	0.0	0.0	0.0	T	0.0	8.4	12.0	T	0.0	0.0	0.0	20.4
1978-79	0.0	0.0	0.0	0.0	0.0	3.3	4.0	6.1	0.0	0.0	0.0	0.0	13.4
1979-80	0.0	0.0	0.0	0.0	T	T	T	1.8	T	0.0	0.0	0.0	1.8
1980-81	0.0	0.0	0.0	0.0	4.0	0.0	T	T	0.0	0.0	0.0	0.0	4.0
1981-82	0.0	0.0	0.0	0.0	0.0	T	1.0	3.9	2.5	0.0	0.0	0.0	7.4
1982-83	0.0	0.0	0.0	0.0	T	T	5.1	4.3	T	0.0	0.0	0.0	9.4
1983-84	0.0	0.0	0.0	0.0	T	1.9	5.6	2.0	T	0.0	0.0	0.0	9.5
1984-85	0.0	0.0	0.0	0.0	T	6.1	1.5	2.3	0.0	0.0	0.0	0.0	9.9
1985-86	0.0	0.0	0.0	0.0	T	2.9	0.0	10.9	0.0	0.0	0.0	0.0	13.8
1986-87	0.0	0.0	0.0	0.0	0.0	T	10.0	1.0	T	0.0	0.0	0.0	11.0
1987-88	0.0	0.0	0.0	0.0	2.0	8.3	12.1	0.2	0.9	0.0	0.0	0.0	23.5
1988-89	0.0	0.0	0.0	0.0	0.6	2.0	4.8	T	4.0	0.6	T	0.0	12.0
1989-90	0.0	0.0	0.0	0.0	T	1.7	0.0	1.7	0.1	0.0	0.0	0.0	3.5
1990-91	0.0	0.0	0.0	0.0	0.0	4.2	T	0.0	T	0.0	0.0	0.0	4.2
1991-92	0.0	0.0	0.0	T	2.1	1.0	5.0	0.0	T	0.0	T	T	8.1
1992-93	0.0	0.0	T		T	3.3	0.4	1.8	T	T		0.0
1993-94	0.0	0.0	0.0	0.1	0.0	T	0.5	T	6.0	0.0	0.0
1994-95	0.0	0.0	0.0	0.0	0.0	0.0	4.9	T	4.5	T	T	T	9.4
1995-96	0.0	0.0		0.0	0.5	4.1	1.0	0.3	T	0.0	T
1996-97					T		6.5			T	0.0	T
1997-98	T	T	0.0	0.0	0.1	2.0	T	T	T	0.0	T	T	2.1
1998-99	0.0	0.0	0.0	T	0.0	1.0	T	0.0	1.3	T	T	0.0	2.3
1999-00	0.0	0.0	T	0.0	0.0	T	9.1	0.0	T	T	0.0	0.0	9.1
2000-01	0.0	0.0	0.0	T	T	8.2	3.4	T	T	0.0	T	0.0	11.6
2001-	0.0	0.0	T	T	3.2	1.5
POR=60 YRS	0.0	0.0	T	T	0.1	1.9	3.0	2.3	T	T	T	T	7.3