Castle Shannon, PA climate
Castle Shannon has chilly, snowy winters and pleasant summers. A typical July afternoon reaches 83°, a January night drops to 21°, and about 44 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Castle Shannon feels like
Winter
Spring
Summer
Fall
Castle Shannon weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 37° | 21° | 3.0" | 13.3" | 17 | 14 | 21° – 39° |
| February | 40° | 23° | 2.6" | 11.7" | 14 | 11 | 19° – 41° |
| March | 50° | 31° | 3.3" | 7.6" | 14 | 5 | 34° – 51° |
| April | 63° | 40° | 3.5" | 1.0" | 14 | 0 | 45° – 56° |
| May | 72° | 49° | 4.1" | 0 | 14 | 0 | 54° – 68° |
| June | 80° | 58° | 4.4" | 0 | 12 | 0 | 65° – 71° |
| July | 83° | 62° | 4.3" | 0 | 11 | 0 | 68° – 77° |
| August | 82° | 61° | 3.8" | 0 | 11 | 0 | 67° – 76° |
| September | 76° | 54° | 3.5" | 0 | 10 | 0 | 61° – 69° |
| October | 64° | 43° | 3.0" | 0.4" | 11 | 0 | 50° – 60° |
| November | 52° | 34° | 2.9" | 2.4" | 12 | 1 | 37° – 48° |
| December | 41° | 26° | 3.2" | 7.7" | 15 | 8 | 23° – 45° |
| Year | 62° | 42° | 41.6" | 44.1" | 154 | 40 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Castle Shannon
Castle Shannon gets 42 inches of rain and melted snow a year. June is the wettest month and February the driest. Rain or snow falls on about 154 days a year. Snow covers the ground about 40 days of the year.
About 193 frost-free days a year
In half of years the last 32° night comes by April 18 and the first one by October 28. That leaves about 193 frost-free days for gardens, longer than 67% of U.S. towns.
Heating and cooling a home in Castle Shannon
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Castle Shannon, 87% of that work is heating and 13% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Castle Shannon and its neighbors
Castle Shannon borders 5 towns with climate data. January nights across them vary by 1.0°. Mount Lebanon has the coldest January nights (21°) and Pittsburgh the hottest July afternoons (85°). Castle Shannon’s January low is 21° and its July high 83°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Castle Shannon compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Castle Shannon averaged 1.2° warmer than the 1900s. The biggest change is in December (+2.4°). The shift is smaller than in 56% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Castle Shannon’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 19° to 41°. June is the most reliable, staying within 7°.
Common questions about Castle Shannon’s climate
What is the coldest month in Castle Shannon?
January, with a typical high of 37° and a low of 21°.
What is the hottest month in Castle Shannon?
July, with a typical high of 83° and a low of 62°. About 8 days a year reach 90°.
How much snow does Castle Shannon get?
About 44 inches in a normal winter, most of it in January.
When is the first frost in Castle Shannon?
In half of years the first 32° night comes by October 28, and the last spring frost by April 18.
What is the rainiest month in Castle Shannon?
June, with 4.4 inches of rain and melted snow. The year totals 42 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Castle Shannon itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Pittsburgh Intl Airport, PA (13 mi, snow) and Pittsburgh Allegheny Co Airport, PA (5 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.