West Mifflin climate — normals and trends

Q: What is the climate of West Mifflin?

West Mifflin has a hot-summer humid continental climate (Köppen Dfa). Over 1940-2025, the average annual temperature is 10.8 °C and it receives 1,230 mm of precipitation per year.

Q: What is the hottest day ever recorded in West Mifflin?

The hottest day measured in West Mifflin between 1940 and 2025 was 16 July 1988, reaching 37.6 °C.

Q: What is the coldest day in West Mifflin?

The coldest day measured in West Mifflin between 1940 and 2025 was 19 January 1994, at -28.2 °C.

Q: Does it snow in West Mifflin?

Yes. West Mifflin gets on average 74.9 cm of snow per year and has around 103 frost days.

Q: Has the climate of West Mifflin warmed?

Yes: West Mifflin warmed by +1.9 °C between 1940 and 2025, a statistically significant trend.

Q: What is the wettest day in West Mifflin?

The wettest day measured in West Mifflin between 1940 and 2025 was 15 October 1954, with 107 mm of rain in 24 hours.

Q: What was the windiest day in West Mifflin?

The windiest day measured in West Mifflin between 1940 and 2025 was 3 April 1975, with winds reaching 44.3 km/h.

Q: What is the warmest month in West Mifflin?

The warmest month in West Mifflin is July (22.4 °C on average); the coldest is January (-1.5 °C).

Q: How much does it rain in West Mifflin?

West Mifflin receives on average 1,230 mm of precipitation per year, spread over about 152 rainy days.

Q: Is it sunny in West Mifflin?

West Mifflin gets on average 8.3 hours of sunshine per day, roughly 3,030 hours per year over 1940-2025.

West Mifflin (United States) has a hot-summer humid continental climate (Dfa) under the Köppen-Geiger classification. Its mean annual temperature is 10.8 °C and it receives 1,230 mm of precipitation per year.

These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.

The warmest month is July (22.4 °C on average) and the coldest is January (-1.5 °C). Rainfall peaks in May.

West Mifflin averages 103 frost days, 19 hot days (≥ 30 °C) and 152 rainy days per year.

West Mifflin has warmed by +1.9 °C between 1940 and 2025, or +0.22 °C per decade. This trend is statistically significant.

The number of frost days there went from about 115 to 91 per year over the period.

The hottest day of the period reached 37.6 °C (on 16 July 1988) and the coldest -28.2 °C (on 19 January 1994).

Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.

Climate normals · ERA5

West MifflinPennsylvania

coords: 40.36°, -79.87°
period: 1940–2025 · 86 yrs

DfaHot-summer humid continentalWarmest monthJulyColdest monthJanuaryWettest monthMayDriest monthOctober

Mean daily temperature

10.8°C

Average daily high

15.9°C

Average daily low

6.2°C

Annual rainfall

1,230mm

Sunshine / day

8.3h

Mean relative humidity

72%

Average peak wind

15.2km/h

Seasonal range

23.9°C

Frost days (< 0 °C)

103 d/yr

Hot days (≥ 30 °C)

19 d/yr

Rainy days (≥ 1 mm)

152 d/yr

Annual snowfall

74.9 cm

Average feels-like high

14.4 °C

Average feels-like low

3.8 °C

Average peak gust

36.3 km/h

Tropical nights (≥ 20 °C)

18 d/yr

Solar radiation

14.0 MJ/m²

Has the climate changed?

One stripe per year, 1940 to 2025

+1.9 °C

since 1940

+0.2 °C per decade · r² = 0.41 · p = < 0.001

19402025

Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).

A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.

Records for the period

Hottest day

37.6 °C

16 July 1988

Coldest day

-28.2 °C

19 January 1994

Wettest day

107 mm

15 October 1954

Windiest day

44.3 km/h

3 April 1975

Strongest gust

113.4 km/h

25 February 1956

Hottest feels-like

42.8 °C

15 July 1995

Coldest feels-like

-34.7 °C

21 January 1985

Snowiest day

32.9 cm

13 March 1993

Sunniest day

14.8 h

24 June 2025

Year	Hottest day	Coldest day	Annual mean	Rainfall	Hot days	Frost days
2025	34.2 °C24 June 2025	-26.4 °C22 January 2025	11.5 °C	1,345 mm	28	101
2024	35.2 °C15 July 2024	-16.6 °C22 January 2024	13.0 °C	1,271 mm	36	76
2023	32.9 °C2 June 2023	-14.4 °C4 February 2023	12.6 °C	1,114 mm	15	75
2022	33.6 °C22 June 2022	-22.8 °C27 January 2022	11.8 °C	1,309 mm	35	100
2021	34.2 °C12 August 2021	-19.3 °C21 February 2021	12.3 °C	1,272 mm	23	92
2020	34.9 °C5 July 2020	-12.2 °C15 February 2020	12.7 °C	1,199 mm	46	70
2019	33.4 °C11 September 2019	-19.4 °C31 January 2019	12.1 °C	1,436 mm	22	96
2018	33.5 °C5 September 2018	-22.7 °C7 January 2018	11.8 °C	1,767 mm	22	107
2017	32.5 °C18 June 2017	-15.2 °C28 December 2017	12.3 °C	1,383 mm	15	80
2016	34.8 °C25 July 2016	-17.5 °C14 February 2016	12.5 °C	1,143 mm	33	89
2015	32.4 °C8 September 2015	-26.0 °C20 February 2015	11.7 °C	1,236 mm	21	93
2014	30.8 °C13 May 2014	-22.3 °C29 January 2014	10.3 °C	1,125 mm	6	111
2013	33.2 °C18 July 2013	-14.5 °C23 January 2013	11.2 °C	1,078 mm	18	113
2012	37.4 °C29 June 2012	-12.5 °C4 January 2012	12.7 °C	1,177 mm	43	85
2011	34.8 °C22 July 2011	-22.4 °C24 January 2011	11.8 °C	1,513 mm	28	93
2010	34.2 °C2 September 2010	-18.9 °C10 January 2010	11.3 °C	1,072 mm	27	104
2009	31.6 °C10 August 2009	-26.2 °C17 January 2009	10.9 °C	1,056 mm	5	100
2008	32.5 °C9 June 2008	-15.8 °C11 February 2008	10.9 °C	1,363 mm	12	105
2007	33.1 °C6 September 2007	-20.5 °C6 February 2007	11.7 °C	1,154 mm	35	98
2006	32.7 °C2 August 2006	-15.5 °C19 February 2006	11.6 °C	1,130 mm	15	85
2005	36.1 °C13 August 2005	-20.4 °C28 January 2005	11.4 °C	1,109 mm	47	96
2004	30.3 °C4 July 2004	-21.9 °C25 January 2004	11.1 °C	1,413 mm	1	97
2003	30.8 °C4 July 2003	-21.9 °C27 January 2003	10.5 °C	1,409 mm	4	105
2002	34.9 °C14 August 2002	-12.6 °C5 March 2002	11.8 °C	1,254 mm	36	92
2001	34.5 °C7 August 2001	-17.2 °C23 January 2001	11.5 °C	970 mm	20	92
2000	30.7 °C11 June 2000	-19.9 °C29 January 2000	10.6 °C	1,141 mm	1	108
1999	34.9 °C5 July 1999	-19.9 °C6 January 1999	11.5 °C	1,007 mm	30	97
1998	31.3 °C25 June 1998	-12.5 °C1 January 1998	12.1 °C	1,186 mm	6	76
1997	31.6 °C17 July 1997	-21.3 °C19 January 1997	10.2 °C	1,149 mm	9	103
1996	30.8 °C30 June 1996	-22.6 °C10 March 1996	10.1 °C	1,521 mm	3	107
1995	36.4 °C15 July 1995	-19.4 °C6 February 1995	10.7 °C	1,261 mm	30	108
1994	34.3 °C19 June 1994	-28.2 °C19 January 1994	10.7 °C	1,391 mm	17	101
1993	35.0 °C9 July 1993	-21.4 °C25 February 1993	11.0 °C	1,193 mm	39	94
1992	31.3 °C9 July 1992	-19.5 °C19 January 1992	10.5 °C	1,180 mm	5	92
1991	35.4 °C2 August 1991	-13.9 °C16 February 1991	12.5 °C	1,084 mm	60	95
1990	32.9 °C4 July 1990	-14.9 °C26 February 1990	12.1 °C	1,459 mm	11	85
1989	32.8 °C25 July 1989	-24.6 °C22 December 1989	10.3 °C	1,327 mm	15	113
1988	37.6 °C16 July 1988	-21.1 °C7 February 1988	10.8 °C	966 mm	46	112
1987	33.9 °C17 August 1987	-22.5 °C25 January 1987	11.3 °C	1,251 mm	23	100
1986	32.7 °C18 July 1986	-19.5 °C8 March 1986	11.3 °C	1,302 mm	14	96
1985	32.7 °C14 August 1985	-27.3 °C21 January 1985	10.8 °C	1,180 mm	8	97
1984	32.0 °C12 June 1984	-24.0 °C21 January 1984	10.8 °C	1,279 mm	10	98
1983	34.6 °C20 August 1983	-23.6 °C25 December 1983	10.7 °C	1,132 mm	32	93
1982	31.2 °C28 June 1982	-26.6 °C17 January 1982	10.8 °C	1,073 mm	10	106
1981	33.3 °C8 July 1981	-22.6 °C13 February 1981	10.2 °C	1,096 mm	10	106
1980	34.1 °C28 June 1980	-19.3 °C26 December 1980	10.2 °C	1,207 mm	20	113
1979	30.3 °C31 July 1979	-23.1 °C11 February 1979	10.0 °C	1,341 mm	2	108
1978	32.6 °C22 July 1978	-17.9 °C4 February 1978	9.7 °C	1,420 mm	10	113
1977	33.3 °C6 July 1977	-25.0 °C17 January 1977	10.5 °C	1,354 mm	13	98
1976	31.5 °C12 June 1976	-21.5 °C3 December 1976	9.8 °C	1,182 mm	11	124
1975	36.0 °C1 August 1975	-22.4 °C10 February 1975	11.0 °C	1,372 mm	16	105
1974	33.9 °C14 July 1974	-19.0 °C5 January 1974	10.9 °C	1,238 mm	18	104
1973	33.8 °C28 August 1973	-18.6 °C17 February 1973	11.3 °C	1,369 mm	17	89
1972	31.9 °C23 July 1972	-21.8 °C16 January 1972	10.0 °C	1,486 mm	8	110
1971	36.1 °C28 June 1971	-19.5 °C2 February 1971	10.8 °C	1,080 mm	11	105
1970	32.8 °C30 June 1970	-20.0 °C22 January 1970	10.7 °C	1,179 mm	20	102
1969	33.8 °C27 June 1969	-17.9 °C25 December 1969	10.3 °C	1,067 mm	17	122
1968	32.8 °C1 July 1968	-21.1 °C2 January 1968	10.1 °C	1,077 mm	19	114
1967	33.1 °C13 June 1967	-24.4 °C8 February 1967	10.2 °C	1,239 mm	10	103
1966	35.9 °C3 July 1966	-22.3 °C29 January 1966	10.1 °C	1,047 mm	28	121
1965	35.7 °C15 August 1965	-21.5 °C17 January 1965	10.6 °C	993 mm	31	109
1964	33.8 °C9 September 1964	-17.5 °C22 February 1964	10.8 °C	1,207 mm	28	111
1963	34.1 °C17 July 1963	-27.5 °C24 January 1963	9.6 °C	981 mm	15	113
1962	33.2 °C20 August 1962	-22.0 °C11 February 1962	10.1 °C	1,238 mm	22	115
1961	32.4 °C2 July 1961	-20.7 °C25 January 1961	10.3 °C	1,267 mm	15	107
1960	31.0 °C2 August 1960	-21.2 °C23 December 1960	10.0 °C	1,081 mm	19	119
1959	35.1 °C9 September 1959	-20.9 °C18 January 1959	11.4 °C	1,166 mm	46	104
1958	31.5 °C4 July 1958	-25.9 °C11 December 1958	9.3 °C	1,179 mm	4	112
1957	33.8 °C3 August 1957	-20.8 °C17 January 1957	10.9 °C	1,127 mm	17	107
1956	31.8 °C2 July 1956	-17.6 °C25 January 1956	10.6 °C	1,456 mm	5	107
1955	34.7 °C2 August 1955	-23.3 °C4 February 1955	11.1 °C	1,138 mm	35	118
1954	34.7 °C14 July 1954	-17.5 °C18 January 1954	10.9 °C	1,194 mm	19	114
1953	36.3 °C3 September 1953	-11.6 °C18 December 1953	11.6 °C	1,131 mm	30	84
1952	35.0 °C26 June 1952	-14.6 °C30 January 1952	11.2 °C	1,279 mm	35	96
1951	33.4 °C30 August 1951	-26.9 °C3 February 1951	10.7 °C	1,249 mm	24	104
1950	31.2 °C26 June 1950	-27.2 °C28 December 1950	10.2 °C	1,481 mm	7	112
1949	33.9 °C4 July 1949	-14.1 °C30 January 1949	11.9 °C	1,185 mm	26	93
1948	34.8 °C27 August 1948	-25.4 °C19 January 1948	10.6 °C	1,381 mm	13	100
1947	31.1 °C13 August 1947	-17.1 °C5 February 1947	10.1 °C	1,020 mm	5	121
1946	31.2 °C19 July 1946	-16.4 °C27 January 1946	11.1 °C	1,158 mm	5	91
1945	31.1 °C30 June 1945	-21.2 °C10 January 1945	10.2 °C	1,484 mm	5	109
1944	32.5 °C12 August 1944	-20.5 °C22 December 1944	10.2 °C	1,245 mm	17	125
1943	30.9 °C12 August 1943	-19.1 °C4 March 1943	9.3 °C	1,133 mm	2	127
1942	31.3 °C19 July 1942	-25.9 °C21 December 1942	9.8 °C	1,514 mm	4	114
1941	32.6 °C28 July 1941	-21.0 °C2 March 1941	9.9 °C	1,042 mm	7	123
1940	33.0 °C30 July 1940	-23.7 °C26 February 1940	8.9 °C	1,318 mm	13	130

Normals computed over complete calendar years 1940–2025.

A specific year

Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?

Year

Across the whole year

Average daily high

16.6 °C

+0.7 °C

Hot days (≥ 30 °C)

28 d/yr

Frost days (< 0 °C)

101 d/yr

-2

Annual rainfall

1345 mm

+115 mm

Month by month

	High	vs. normal	Precipitation	vs. normal
Jan	-0.9 °C	-3.4 °C	54 mm	-34 mm
Feb	4.7 °C	+0.3 °C	115 mm	+29 mm
Mar	14.7 °C	+5.0 °C	77 mm	-35 mm
Apr	17.9 °C	+1.7 °C	140 mm	+27 mm
May	20.3 °C	-1.0 °C	239 mm	+112 mm
Jun	27.4 °C	+1.7 °C	158 mm	+32 mm
Jul	29.3 °C	+1.6 °C	144 mm	+24 mm
Aug	26.9 °C	0.0 °C	51 mm	-50 mm
Sep	25.6 °C	+2.1 °C	120 mm	+28 mm
Oct	17.6 °C	+0.3 °C	89 mm	+6 mm
Nov	10.2 °C	-0.3 °C	71 mm	-21 mm
Dec	4.3 °C	-0.4 °C	89 mm	-2 mm

The year's extremes

Hottest day

34.2 °C

24 Jun 2025

Coldest day

-26.4 °C

22 Jan 2025

Wettest day

63.0 mm

25 Sep 2025

Windiest day

34.3 km/h

15 Apr 2025

Strongest gust

85.7 km/h

15 Apr 2025

Hottest feels-like

39.0 °C

25 Jun 2025

Coldest feels-like

-31.4 °C

22 Jan 2025

Snowiest day

8.7 cm

2 Dec 2025

Sunniest day

14.8 h

24 Jun 2025

What was the weather like that day?

Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.

Date

Frequently asked questions

What is the climate of West Mifflin?

West Mifflin has a hot-summer humid continental climate (Köppen Dfa). Over 1940-2025, the average annual temperature is 10.8 °C and it receives 1,230 mm of precipitation per year.

What is the hottest day ever recorded in West Mifflin?

The hottest day measured in West Mifflin between 1940 and 2025 was 16 July 1988, reaching 37.6 °C.

What is the coldest day in West Mifflin?

The coldest day measured in West Mifflin between 1940 and 2025 was 19 January 1994, at -28.2 °C.

Does it snow in West Mifflin?

Yes. West Mifflin gets on average 74.9 cm of snow per year and has around 103 frost days.

Has the climate of West Mifflin warmed?

Yes: West Mifflin warmed by +1.9 °C between 1940 and 2025, a statistically significant trend.

What is the wettest day in West Mifflin?

The wettest day measured in West Mifflin between 1940 and 2025 was 15 October 1954, with 107 mm of rain in 24 hours.

What was the windiest day in West Mifflin?

The windiest day measured in West Mifflin between 1940 and 2025 was 3 April 1975, with winds reaching 44.3 km/h.

What is the warmest month in West Mifflin?

The warmest month in West Mifflin is July (22.4 °C on average); the coldest is January (-1.5 °C).

How much does it rain in West Mifflin?

West Mifflin receives on average 1,230 mm of precipitation per year, spread over about 152 rainy days.

Is it sunny in West Mifflin?

West Mifflin gets on average 8.3 hours of sunshine per day, roughly 3,030 hours per year over 1940-2025.

What is the biggest single-day snowfall in West Mifflin?

The heaviest 24-hour snowfall measured in West Mifflin between 1940 and 2025 was 13 March 1993, with 32.9 cm.

Are there tropical nights in West Mifflin?

Yes: West Mifflin has on average 18 tropical nights per year (temperature staying above 20 °C), over 1940-2025.

What was the most extreme apparent temperature in West Mifflin?

In West Mifflin, between 1940 and 2025, the highest apparent temperature reached 42.8 °C on 15 July 1995, and the lowest was -34.7 °C on 21 January 1985.

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