Back Mountain climate — normals and trends
Back Mountain (United States) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 9.3 °C and it receives 1,042 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 (21.7 °C on average) and the coldest is January (-3.6 °C). Rainfall peaks in May.
Back Mountain averages 119 frost days, 12 hot days (≥ 30 °C) and 128 rainy days per year.
Back Mountain has warmed by +2.1 °C between 1940 and 2025, or +0.25 °C per decade. This trend is statistically significant.
The number of frost days there went from about 132 to 106 per year over the period.
The hottest day of the period reached 37.3 °C (on 3 July 1966) and the coldest -30.4 °C (on 19 January 1997).
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
Back MountainPennsylvania
- coords
- 41.34°, -76.00°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
9.3°C
Average daily high
14.0°C
Average daily low
4.8°C
Annual rainfall
1,042mm
Sunshine / day
8.5h
Mean relative humidity
71%
Average peak wind
15.7km/h
Seasonal range
25.3°C
Frost days (< 0 °C)
119 d/yr
Hot days (≥ 30 °C)
12 d/yr
Rainy days (≥ 1 mm)
128 d/yr
Annual snowfall
102.4 cm
Average feels-like high
12.1 °C
Average feels-like low
2.2 °C
Average peak gust
39.7 km/h
Tropical nights (≥ 20 °C)
11 d/yr
Solar radiation
14.2 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.1 °C
since 1940
+0.3 °C per decade · r² = 0.50 · p = < 0.001
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
37.3 °C
3 July 1966
Coldest day
-30.4 °C
19 January 1997
Wettest day
128 mm
1 September 2021
Windiest day
50.0 km/h
15 October 1954
Strongest gust
138.2 km/h
15 October 1954
Hottest feels-like
41.2 °C
26 August 1948
Coldest feels-like
-36.0 °C
19 January 1997
Snowiest day
35.0 cm
13 March 1993
Sunniest day
14.4 h
26 June 2018
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?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | -1.1 °C | -1.2 °C | 26 mm | -49 mm |
| Feb | 2.0 °C | +0.3 °C | 67 mm | -4 mm |
| Mar | 12.2 °C | +5.3 °C | 63 mm | -27 mm |
| Apr | 15.5 °C | +1.7 °C | 81 mm | -13 mm |
| May | 18.9 °C | -0.8 °C | 175 mm | +76 mm |
| Jun | 25.4 °C | +1.2 °C | 97 mm | +4 mm |
| Jul | 28.4 °C | +1.7 °C | 92 mm | +3 mm |
| Aug | 25.8 °C | +0.1 °C | 39 mm | -52 mm |
| Sep | 24.4 °C | +2.6 °C | 50 mm | -40 mm |
| Oct | 16.4 °C | +0.8 °C | 110 mm | +28 mm |
| Nov | 8.8 °C | +0.1 °C | 42 mm | -43 mm |
| Dec | 0.7 °C | -1.8 °C | 71 mm | -12 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Back Mountain?
Back Mountain has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 9.3 °C and it receives 1,042 mm of precipitation per year.
What is the hottest day ever recorded in Back Mountain?
The hottest day measured in Back Mountain between 1940 and 2025 was 3 July 1966, reaching 37.3 °C.
What is the coldest day in Back Mountain?
The coldest day measured in Back Mountain between 1940 and 2025 was 19 January 1997, at -30.4 °C.
Does it snow in Back Mountain?
Yes. Back Mountain gets on average 102.4 cm of snow per year and has around 119 frost days.
Has the climate of Back Mountain warmed?
Yes: Back Mountain warmed by +2.1 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Back Mountain?
The wettest day measured in Back Mountain between 1940 and 2025 was 1 September 2021, with 128 mm of rain in 24 hours.
What was the windiest day in Back Mountain?
The windiest day measured in Back Mountain between 1940 and 2025 was 15 October 1954, with winds reaching 50.0 km/h.
What is the warmest month in Back Mountain?
The warmest month in Back Mountain is July (21.7 °C on average); the coldest is January (-3.6 °C).
How much does it rain in Back Mountain?
Back Mountain receives on average 1,042 mm of precipitation per year, spread over about 128 rainy days.
Is it sunny in Back Mountain?
Back Mountain gets on average 8.5 hours of sunshine per day, roughly 3,103 hours per year over 1940-2025.
What is the biggest single-day snowfall in Back Mountain?
The heaviest 24-hour snowfall measured in Back Mountain between 1940 and 2025 was 13 March 1993, with 35.0 cm.
Are there tropical nights in Back Mountain?
Yes: Back Mountain has on average 11 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Back Mountain?
In Back Mountain, between 1940 and 2025, the highest apparent temperature reached 41.2 °C on 26 August 1948, and the lowest was -36.0 °C on 19 January 1997.
Compare Back Mountain with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Back Mountain