Allentown climate — normals and trends

Q: What is the climate of Allentown?

Allentown has a hot-summer humid continental climate (Köppen Dfa). Over 1940-2025, the average annual temperature is 11.4 °C and it receives 1,143 mm of precipitation per year.

Q: What is the hottest day ever recorded in Allentown?

The hottest day measured in Allentown between 1940 and 2025 was 22 July 2011, reaching 40.5 °C.

Q: What is the coldest day in Allentown?

The coldest day measured in Allentown between 1940 and 2025 was 22 January 1984, at -27.1 °C.

Q: Does it snow in Allentown?

Yes. Allentown gets on average 70.4 cm of snow per year and has around 99 frost days.

Q: Has the climate of Allentown warmed?

Yes: Allentown warmed by +2.0 °C between 1940 and 2025, a statistically significant trend.

Q: What is the wettest day in Allentown?

The wettest day measured in Allentown between 1940 and 2025 was 8 October 2005, with 136 mm of rain in 24 hours.

Q: What was the windiest day in Allentown?

The windiest day measured in Allentown between 1940 and 2025 was 29 October 2012, with winds reaching 48.0 km/h.

Q: What is the warmest month in Allentown?

The warmest month in Allentown is July (23.8 °C on average); the coldest is January (-1.3 °C).

Q: How much does it rain in Allentown?

Allentown receives on average 1,143 mm of precipitation per year, spread over about 121 rainy days.

Q: Is it sunny in Allentown?

Allentown gets on average 8.7 hours of sunshine per day, roughly 3,175 hours per year over 1940-2025.

Allentown (United States) has a hot-summer humid continental climate (Dfa) under the Köppen-Geiger classification. Its mean annual temperature is 11.4 °C and it receives 1,143 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 (23.8 °C on average) and the coldest is January (-1.3 °C). Rainfall peaks in May.

Allentown averages 99 frost days, 33 hot days (≥ 30 °C) and 121 rainy days per year.

Allentown has warmed by +2.0 °C between 1940 and 2025, or +0.23 °C per decade. This trend is statistically significant.

The number of frost days there went from about 110 to 88 per year over the period.

The hottest day of the period reached 40.5 °C (on 22 July 2011) and the coldest -27.1 °C (on 22 January 1984).

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

AllentownPennsylvania

coords: 40.61°, -75.49°
period: 1940–2025 · 86 yrs

DfaHot-summer humid continentalWarmest monthJulyColdest monthJanuaryWettest monthMayDriest monthFebruary

Mean daily temperature

11.4°C

Average daily high

16.3°C

Average daily low

6.7°C

Annual rainfall

1,143mm

Sunshine / day

8.7h

Mean relative humidity

68%

Average peak wind

15.5km/h

Seasonal range

25.1°C

Frost days (< 0 °C)

99 d/yr

Hot days (≥ 30 °C)

33 d/yr

Rainy days (≥ 1 mm)

121 d/yr

Annual snowfall

70.4 cm

Average feels-like high

14.8 °C

Average feels-like low

4.3 °C

Average peak gust

36.7 km/h

Tropical nights (≥ 20 °C)

29 d/yr

Solar radiation

14.6 MJ/m²

Has the climate changed?

One stripe per year, 1940 to 2025

+2.0 °C

since 1940

+0.2 °C per decade · r² = 0.46 · 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

40.5 °C

22 July 2011

Coldest day

-27.1 °C

22 January 1984

Wettest day

136 mm

8 October 2005

Windiest day

48.0 km/h

29 October 2012

Strongest gust

124.6 km/h

15 October 1954

Hottest feels-like

44.5 °C

22 July 2011

Coldest feels-like

-32.2 °C

22 January 1984

Snowiest day

32.3 cm

23 January 2016

Sunniest day

14.1 h

4 July 2025

Year	Hottest day	Coldest day	Annual mean	Rainfall	Hot days	Frost days
2025	37.2 °C24 June 2025	-15.0 °C22 January 2025	12.3 °C	995 mm	45	98
2024	36.6 °C16 July 2024	-13.6 °C23 December 2024	13.1 °C	1,121 mm	37	69
2023	35.2 °C2 June 2023	-13.3 °C4 February 2023	13.2 °C	1,222 mm	32	67
2022	36.4 °C24 July 2022	-15.3 °C24 December 2022	12.5 °C	1,235 mm	50	99
2021	36.8 °C30 June 2021	-11.6 °C8 February 2021	12.9 °C	1,163 mm	45	87
2020	35.7 °C5 July 2020	-14.6 °C19 December 2020	13.0 °C	1,157 mm	41	67
2019	35.2 °C21 July 2019	-20.2 °C7 March 2019	12.3 °C	1,331 mm	32	103
2018	35.9 °C2 July 2018	-19.1 °C7 January 2018	12.3 °C	1,612 mm	45	93
2017	35.3 °C13 June 2017	-11.8 °C29 December 2017	12.7 °C	1,094 mm	38	83
2016	36.3 °C23 July 2016	-16.3 °C14 February 2016	13.0 °C	947 mm	58	87
2015	36.0 °C19 July 2015	-21.8 °C24 February 2015	12.3 °C	952 mm	53	94
2014	33.8 °C2 July 2014	-20.7 °C4 January 2014	10.9 °C	1,051 mm	26	108
2013	35.4 °C19 July 2013	-12.9 °C23 January 2013	11.7 °C	1,076 mm	31	103
2012	39.3 °C18 July 2012	-12.3 °C4 January 2012	13.2 °C	936 mm	50	79
2011	40.5 °C22 July 2011	-19.5 °C24 January 2011	12.4 °C	1,610 mm	39	96
2010	38.8 °C6 July 2010	-11.3 °C10 January 2010	12.8 °C	1,056 mm	73	91
2009	33.9 °C17 August 2009	-15.3 °C17 January 2009	11.5 °C	1,153 mm	18	92
2008	37.2 °C10 June 2008	-13.7 °C11 February 2008	11.8 °C	1,276 mm	33	96
2007	35.9 °C8 August 2007	-14.5 °C5 February 2007	12.1 °C	1,057 mm	51	96
2006	37.6 °C1 August 2006	-11.5 °C19 February 2006	12.8 °C	1,200 mm	44	79
2005	36.7 °C27 July 2005	-19.4 °C29 January 2005	12.0 °C	1,050 mm	55	93
2004	33.7 °C9 June 2004	-19.8 °C25 January 2004	11.5 °C	1,241 mm	23	96
2003	33.5 °C26 June 2003	-20.5 °C18 January 2003	10.7 °C	1,456 mm	18	101
2002	38.1 °C2 August 2002	-11.4 °C7 December 2002	12.3 °C	1,141 mm	47	90
2001	38.6 °C9 August 2001	-18.2 °C23 January 2001	12.2 °C	769 mm	40	97
2000	32.6 °C10 July 2000	-16.0 °C30 January 2000	11.0 °C	1,020 mm	13	99
1999	37.2 °C5 July 1999	-13.1 °C23 February 1999	12.2 °C	1,115 mm	45	88
1998	33.5 °C22 July 1998	-18.6 °C1 January 1998	12.9 °C	1,048 mm	43	71
1997	36.9 °C17 July 1997	-18.1 °C19 January 1997	11.2 °C	906 mm	37	102
1996	33.8 °C20 May 1996	-19.6 °C5 February 1996	10.6 °C	1,534 mm	7	97
1995	39.3 °C15 July 1995	-19.2 °C8 February 1995	11.7 °C	1,058 mm	45	105
1994	35.4 °C19 June 1994	-22.7 °C19 January 1994	11.4 °C	1,330 mm	32	96
1993	36.6 °C10 July 1993	-15.4 °C19 February 1993	11.6 °C	1,212 mm	56	103
1992	36.1 °C14 July 1992	-13.6 °C19 January 1992	10.9 °C	982 mm	22	97
1991	37.9 °C23 July 1991	-14.4 °C22 January 1991	12.7 °C	1,026 mm	63	95
1990	35.3 °C4 July 1990	-14.4 °C26 February 1990	12.4 °C	1,239 mm	20	79
1989	33.1 °C10 September 1989	-16.0 °C22 December 1989	10.8 °C	1,356 mm	22	110
1988	38.2 °C17 July 1988	-23.2 °C11 January 1988	11.0 °C	983 mm	52	106
1987	35.9 °C21 July 1987	-22.0 °C28 January 1987	11.4 °C	1,188 mm	39	101
1986	36.4 °C7 July 1986	-15.3 °C29 January 1986	11.4 °C	1,179 mm	28	102
1985	34.6 °C14 August 1985	-23.4 °C21 January 1985	11.4 °C	965 mm	22	99
1984	33.8 °C13 June 1984	-27.1 °C22 January 1984	11.0 °C	1,376 mm	19	96
1983	36.4 °C20 August 1983	-18.7 °C25 December 1983	11.3 °C	1,446 mm	49	94
1982	33.0 °C19 July 1982	-21.1 °C17 January 1982	10.7 °C	1,046 mm	12	105
1981	34.3 °C16 June 1981	-24.0 °C12 January 1981	11.0 °C	956 mm	29	99
1980	37.4 °C21 July 1980	-18.0 °C25 December 1980	11.0 °C	873 mm	45	106
1979	34.9 °C10 August 1979	-23.6 °C18 February 1979	11.1 °C	1,322 mm	22	89
1978	35.5 °C23 July 1978	-19.0 °C5 February 1978	10.0 °C	1,395 mm	21	110
1977	35.1 °C19 July 1977	-20.2 °C17 January 1977	10.9 °C	1,237 mm	27	105
1976	32.7 °C28 June 1976	-18.5 °C23 January 1976	10.7 °C	1,052 mm	29	115
1975	33.9 °C2 August 1975	-16.8 °C10 February 1975	11.6 °C	1,388 mm	16	96
1974	34.3 °C10 June 1974	-16.3 °C14 January 1974	11.4 °C	1,107 mm	24	97
1973	34.7 °C28 August 1973	-16.2 °C19 December 1973	11.7 °C	1,345 mm	25	84
1972	34.0 °C23 July 1972	-19.4 °C23 February 1972	10.7 °C	1,454 mm	22	104
1971	35.4 °C8 July 1971	-19.5 °C3 February 1971	11.3 °C	1,197 mm	33	96
1970	33.7 °C23 September 1970	-18.9 °C20 January 1970	11.1 °C	1,015 mm	35	106
1969	33.7 °C29 May 1969	-16.2 °C25 December 1969	10.8 °C	1,250 mm	18	116
1968	36.0 °C1 July 1968	-20.2 °C2 January 1968	11.0 °C	924 mm	45	102
1967	33.7 °C16 June 1967	-24.3 °C13 February 1967	10.3 °C	1,098 mm	18	107
1966	40.1 °C3 July 1966	-17.1 °C29 January 1966	10.9 °C	957 mm	52	107
1965	34.8 °C25 July 1965	-21.7 °C5 February 1965	10.6 °C	759 mm	31	107
1964	36.2 °C30 June 1964	-16.8 °C15 January 1964	11.0 °C	992 mm	36	109
1963	35.6 °C27 June 1963	-23.9 °C29 January 1963	10.3 °C	916 mm	24	107
1962	34.5 °C8 July 1962	-20.3 °C11 February 1962	10.2 °C	1,007 mm	29	119
1961	33.1 °C13 June 1961	-22.7 °C22 January 1961	10.7 °C	1,149 mm	27	102
1960	32.3 °C29 August 1960	-21.5 °C23 December 1960	10.4 °C	1,243 mm	14	118
1959	35.1 °C29 June 1959	-15.5 °C23 December 1959	11.8 °C	1,136 mm	44	104
1958	32.5 °C2 July 1958	-20.6 °C11 February 1958	10.2 °C	1,216 mm	24	93
1957	36.3 °C21 July 1957	-22.5 °C15 January 1957	11.5 °C	950 mm	35	96
1956	34.3 °C14 June 1956	-10.2 °C28 January 1956	10.8 °C	1,178 mm	20	101
1955	38.3 °C22 July 1955	-18.3 °C3 February 1955	11.6 °C	991 mm	44	111
1954	37.9 °C31 July 1954	-20.3 °C18 January 1954	11.5 °C	953 mm	32	103
1953	39.1 °C2 September 1953	-10.8 °C18 December 1953	12.2 °C	1,071 mm	43	89
1952	36.2 °C26 June 1952	-13.7 °C30 January 1952	11.4 °C	1,353 mm	31	95
1951	33.2 °C27 July 1951	-19.9 °C17 December 1951	11.2 °C	1,220 mm	23	94
1950	32.8 °C26 June 1950	-16.5 °C27 December 1950	10.7 °C	1,123 mm	18	112
1949	35.7 °C4 July 1949	-16.0 °C3 February 1949	12.3 °C	1,025 mm	41	89
1948	36.5 °C26 August 1948	-22.1 °C19 January 1948	10.5 °C	1,254 mm	21	103
1947	33.3 °C14 August 1947	-15.1 °C5 February 1947	10.8 °C	1,088 mm	15	116
1946	32.7 °C19 July 1946	-16.5 °C28 January 1946	11.5 °C	1,075 mm	14	88
1945	33.4 °C1 July 1945	-19.5 °C25 January 1945	10.6 °C	1,473 mm	13	105
1944	35.1 °C5 August 1944	-17.3 °C22 December 1944	10.7 °C	1,118 mm	39	117
1943	33.6 °C25 June 1943	-23.3 °C16 February 1943	10.2 °C	956 mm	27	127
1942	33.3 °C19 July 1942	-21.1 °C11 January 1942	10.6 °C	1,266 mm	8	111
1941	34.4 °C28 July 1941	-15.7 °C10 February 1941	10.9 °C	978 mm	24	114
1940	33.1 °C26 July 1940	-17.1 °C20 January 1940	9.7 °C	1,293 mm	9	115

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

17.3 °C

+1.0 °C

Hot days (≥ 30 °C)

45 d/yr

+12

Frost days (< 0 °C)

98 d/yr

-1

Annual rainfall

995 mm

-149 mm

Month by month

	High	vs. normal	Precipitation	vs. normal
Jan	1.6 °C	-1.0 °C	25 mm	-60 mm
Feb	4.8 °C	+0.5 °C	79 mm	-2 mm
Mar	14.5 °C	+5.1 °C	89 mm	-13 mm
Apr	17.8 °C	+1.8 °C	99 mm	-3 mm
May	21.3 °C	-0.4 °C	179 mm	+73 mm
Jun	27.4 °C	+0.8 °C	92 mm	-3 mm
Jul	31.3 °C	+2.2 °C	130 mm	+26 mm
Aug	27.8 °C	-0.2 °C	24 mm	-75 mm
Sep	26.4 °C	+2.3 °C	71 mm	-25 mm
Oct	18.8 °C	+1.0 °C	91 mm	+4 mm
Nov	11.4 °C	+0.3 °C	50 mm	-40 mm
Dec	3.2 °C	-1.7 °C	67 mm	-28 mm

The year's extremes

Hottest day

37.2 °C

24 Jun 2025

Coldest day

-15.0 °C

22 Jan 2025

Wettest day

48.7 mm

30 Oct 2025

Windiest day

32.1 km/h

11 Nov 2025

Strongest gust

77.4 km/h

30 Oct 2025

Hottest feels-like

42.2 °C

23 Jun 2025

Coldest feels-like

-20.1 °C

22 Jan 2025

Snowiest day

6.2 cm

14 Dec 2025

Sunniest day

14.1 h

4 Jul 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 Allentown?

Allentown has a hot-summer humid continental climate (Köppen Dfa). Over 1940-2025, the average annual temperature is 11.4 °C and it receives 1,143 mm of precipitation per year.

What is the hottest day ever recorded in Allentown?

The hottest day measured in Allentown between 1940 and 2025 was 22 July 2011, reaching 40.5 °C.

What is the coldest day in Allentown?

The coldest day measured in Allentown between 1940 and 2025 was 22 January 1984, at -27.1 °C.

Does it snow in Allentown?

Yes. Allentown gets on average 70.4 cm of snow per year and has around 99 frost days.

Has the climate of Allentown warmed?

Yes: Allentown warmed by +2.0 °C between 1940 and 2025, a statistically significant trend.

What is the wettest day in Allentown?

The wettest day measured in Allentown between 1940 and 2025 was 8 October 2005, with 136 mm of rain in 24 hours.

What was the windiest day in Allentown?

The windiest day measured in Allentown between 1940 and 2025 was 29 October 2012, with winds reaching 48.0 km/h.

What is the warmest month in Allentown?

The warmest month in Allentown is July (23.8 °C on average); the coldest is January (-1.3 °C).

How much does it rain in Allentown?

Allentown receives on average 1,143 mm of precipitation per year, spread over about 121 rainy days.

Is it sunny in Allentown?

Allentown gets on average 8.7 hours of sunshine per day, roughly 3,175 hours per year over 1940-2025.

What is the biggest single-day snowfall in Allentown?

The heaviest 24-hour snowfall measured in Allentown between 1940 and 2025 was 23 January 2016, with 32.3 cm.

Are there tropical nights in Allentown?

Yes: Allentown has on average 29 tropical nights per year (temperature staying above 20 °C), over 1940-2025.

What was the most extreme apparent temperature in Allentown?

In Allentown, between 1940 and 2025, the highest apparent temperature reached 44.5 °C on 22 July 2011, and the lowest was -32.2 °C on 22 January 1984.

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