Historical Climate Data

Temperature Summary
Station: 470045 AFTON, WI
1971-2000 NCDC Normals

Element	JAN	FEB	MAR	APR	MAY	JUN	JUL	AUG	SEP	OCT	NOV	DEC	ANN
Max °F	26.7	32.0	44.7	57.9	70.8	80.6	83.8	81.3	74.1	61.3	45.1	31.4	57.5
Min °F	8.6	13.6	25.2	35.3	46.6	55.6	60.4	58.1	48.8	37.9	27.6	15.3	36.1
Mean °F	17.7	22.8	35.0	46.6	58.7	68.1	72.1	69.7	61.5	49.6	36.4	23.4	46.8
HDD base 65	1469	1181	933	554	242	39	8	35	144	482	859	1292	7238
CDD base 65	0	0	0	1	48	131	228	181	37	3	0	0	629

Temperature Extremes
Period of Record: 1987-2001

Month	High Mean°F	Year	Low Mean°F	Year	1-Day Max°F	Date	1-Day Min°F	Date
JAN	28.9	1990	9.5	1994	59	01-31-1989	-28	01-19-1994
FEB	35.2	1998	13.0	1989	69	02-26-2000	-31	02-03-1996
MAR	42.0	2000	28.4	1996	80	03-30-1998	-3	03-08-1996
APR	51.5	2001	42.6	1995	85	04-25-1990	15	04-05-1995
MAY	64.1	1991	52.7	1997	92	05-31-1988	27	05-06-1989
JUN	71.5	1991	65.3	1992	101	06-20-1988	36	06-01-1993
JUL	76.4	1999	67.4	1992	101	07-15-1988	45	07-02-2001
AUG	76.9	1995	64.0	1992	102	08-01-1988	43	08-16-1992
SEP	65.3	1998	56.5	1993	96	09-02-2000	28	09-23-1995
OCT	53.7	2000	42.3	1987	88	10-06-1997	14	10-29-1988
NOV	46.2	2001	28.4	1995	74	11-09-1999	-4	11-29-1995
DEC	31.5	2001	11.4	2000	67	12-06-2001	-25	12-25-2000

Annual	51.0	1998	44.6	1996	102	08-01-1988	-31	02-03-1996
Winter	29.6	1998	16.3	1994	69	02-26-1900	-31	02-03-1996
Spring	50.3	1991	41.8	1996	92	05-31-1988	-3	03-08-1996
Summer	74.1	1995	65.6	1992	102	08-01-1988	36	06-01-1993
Fall	52.8	1998	46.1	1995	96	09-02-1900	-4	11-29-1995

Temperature Threshold Climatology
Derived from 1987-2000 Averages

*Annual/seasonal totals may differ from the sum of the monthly totals due to rounding.

Month	# Days Max ≥ 90°F	# Days Max ≤ 32°F	# Days Min ≤ 32°F	# Days Min ≤ 0°F
JAN	0.0	19.1	30.0	8.1
FEB	0.0	13.0	26.2	5.2
MAR	0.0	4.5	24.9	0.3
APR	0.0	0.2	11.9	0.0
MAY	0.2	0.0	1.0	0.0
JUN	3.7	0.0	0.0	0.0
JUL	5.8	0.0	0.0	0.0
AUG	3.4	0.0	0.0	0.0
SEP	1.2	0.0	0.9	0.0
OCT	0.0	0.0	10.9	0.0
NOV	0.0	4.2	22.2	0.2
DEC	0.0	15.0	29.4	4.4

Annual	14.3	55.6	157.6	18.1
Winter	0.0	47.0	85.6	17.6
Spring	0.2	4.8	37.8	0.3
Summer	12.8	0.0	0.0	0.0
Fall	1.2	4.0	33.2	0.1