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West Mifflin, Pennsylvania climate
Cfa Humid subtropical
West Mifflin has a seasonal cool-temperate climate (Humid subtropical, Köppen Cfa). The hottest month is July with an average daily high near 85°F, while the coldest is January averaging around 21°F at night. Precipitation is fairly even year-round, totalling about 42 inches.
Temperature & precipitation
Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figuresClear vs cloudy days
Share of days each month that are clear, partly cloudy or cloudy · 1991–2020 · hover a month for the day countsWest Mifflin climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 39 | 42 | 51 | 64 | 74 | 81 | 85 | 83 | 77 | 65 | 53 | 43 |
| Avg temp (°F) | 30 | 32 | 40 | 51 | 61 | 69 | 73 | 72 | 65 | 53 | 42 | 34 |
| Avg low (°F) | 21 | 22 | 29 | 38 | 47 | 57 | 61 | 60 | 53 | 42 | 32 | 25 |
| Precipitation (in) | 3.0 | 2.5 | 3.2 | 3.8 | 4.0 | 5.0 | 4.1 | 3.5 | 3.5 | 3.2 | 3.0 | 3.6 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°F) | 39 | 42 | 51 | 64 | 74 | 81 |
| Avg temp (°F) | 30 | 32 | 40 | 51 | 61 | 69 |
| Avg low (°F) | 21 | 22 | 29 | 38 | 47 | 57 |
| Precipitation (in) | 3.0 | 2.5 | 3.2 | 3.8 | 4.0 | 5.0 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°F) | 85 | 83 | 77 | 65 | 53 | 43 |
| Avg temp (°F) | 73 | 72 | 65 | 53 | 42 | 34 |
| Avg low (°F) | 61 | 60 | 53 | 42 | 32 | 25 |
| Precipitation (in) | 4.1 | 3.5 | 3.5 | 3.2 | 3.0 | 3.6 |
How often — frequency of weather events
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 14 | 11 | 13 | 14 | 14 | 13 | 11 | 10 | 10 | 11 | 11 | 13 |
| Days with high ≥ 90°F (days) | — | — | — | — | 0.4 | 2 | 5 | 4 | 1 | 0.1 | — | — |
| Days with low ≤ 32°F (days) | 24 | 21 | 19 | 7 | 1 | 0.0 | — | — | 0.2 | 3 | 15 | 22 |
| Days with snowfall ≥ 1 in (days) | 2 | 2 | 0.5 | — | — | — | — | — | — | — | 0.2 | 0.9 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 14 | 11 | 13 | 14 | 14 | 13 |
| Days with high ≥ 90°F (days) | — | — | — | — | 0.4 | 2 |
| Days with low ≤ 32°F (days) | 24 | 21 | 19 | 7 | 1 | 0.0 |
| Days with snowfall ≥ 1 in (days) | 2 | 2 | 0.5 | — | — | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 11 | 10 | 10 | 11 | 11 | 13 |
| Days with high ≥ 90°F (days) | 5 | 4 | 1 | 0.1 | — | — |
| Days with low ≤ 32°F (days) | — | — | 0.2 | 3 | 15 | 22 |
| Days with snowfall ≥ 1 in (days) | — | — | — | — | 0.2 | 0.9 |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 77 | 75 | 72 | 69 | 68 | 63 | 59 | 57 | 56 | 63 | 70 | 77 |
| Clear days (≤ 30% cloud) | 2 | 2 | 4 | 4 | 4 | 5 | 6 | 6 | 8 | 6 | 4 | 2 |
| Partly cloudy days (30–70%) | 8 | 8 | 8 | 8 | 9 | 11 | 13 | 13 | 10 | 9 | 8 | 8 |
| Cloudy days (≥ 70%) | 21 | 19 | 19 | 18 | 18 | 14 | 13 | 12 | 12 | 15 | 18 | 21 |
| Relative humidity (%) | 88 | 86 | 82 | 78 | 78 | 76 | 71 | 68 | 70 | 75 | 81 | 86 |
| Wind speed (mph) | 1.6 | 1.9 | 1.4 | 0.6 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.9 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 77 | 75 | 72 | 69 | 68 | 63 |
| Clear days (≤ 30% cloud) | 2 | 2 | 4 | 4 | 4 | 5 |
| Partly cloudy days (30–70%) | 8 | 8 | 8 | 8 | 9 | 11 |
| Cloudy days (≥ 70%) | 21 | 19 | 19 | 18 | 18 | 14 |
| Relative humidity (%) | 88 | 86 | 82 | 78 | 78 | 76 |
| Wind speed (mph) | 1.6 | 1.9 | 1.4 | 0.6 | 0.4 | 0.4 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 59 | 57 | 56 | 63 | 70 | 77 |
| Clear days (≤ 30% cloud) | 6 | 6 | 8 | 6 | 4 | 2 |
| Partly cloudy days (30–70%) | 13 | 13 | 10 | 9 | 8 | 8 |
| Cloudy days (≥ 70%) | 13 | 12 | 12 | 15 | 18 | 21 |
| Relative humidity (%) | 71 | 68 | 70 | 75 | 81 | 86 |
| Wind speed (mph) | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.9 |
Methodology & sources
Temperature & precipitation — the official 1991–2020 climate normals from NOAA's U.S. Climate Normals, measured at Mckeesport (NOAA GHCN station USC00365573), about 3 km from the city centre.
Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.