Lower Merion, PA climate
Lower Merion has chilly winters and warm summers, with plenty of rain. A typical July afternoon reaches 87°, a January night drops to 24°, and about 8 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Lower Merion feels like
Winter
Spring
Summer
Fall
Lower Merion 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 | 40° | 24° | 3.4" | 2.7" | 9 | 3 | 24° – 40° |
| February | 43° | 26° | 2.8" | 2.4" | 9 | 3 | 23° – 42° |
| March | 51° | 33° | 4.1" | 0.6" | 10 | 2 | 37° – 50° |
| April | 64° | 42° | 3.7" | 0.1" | 11 | 0 | 49° – 58° |
| May | 73° | 52° | 3.9" | 0 | 11 | 0 | 58° – 68° |
| June | 82° | 62° | 4.4" | 0 | 9 | 0 | 69° – 76° |
| July | 87° | 67° | 4.8" | 0 | 9 | 0 | 72° – 81° |
| August | 85° | 65° | 4.5" | 0 | 9 | 0 | 70° – 79° |
| September | 78° | 58° | 4.7" | 0 | 8 | 0 | 64° – 72° |
| October | 66° | 47° | 4.0" | 0 | 9 | 0 | 52° – 63° |
| November | 55° | 37° | 3.3" | 0.2" | 8 | 0 | 40° – 51° |
| December | 45° | 29° | 4.3" | 1.6" | 10 | 1 | 29° – 49° |
| Year | 64° | 45° | 47.9" | 7.6" | 111 | 9 |
“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 Lower Merion
Lower Merion gets 48 inches of rain and melted snow a year. July is the wettest month and February the driest. Rain or snow falls on about 111 days a year. Snow covers the ground about 9 days of the year.
About 199 frost-free days a year
In half of years the last 32° night comes by April 15 and the first one by October 31. That leaves about 199 frost-free days for gardens, longer than 72% of U.S. towns.
Heating and cooling a home in Lower Merion
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Lower Merion, 81% of that work is heating and 19% 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.
Lower Merion and its neighbors
Lower Merion borders 7 towns with climate data. January nights across them vary by 1.9°. Upper Merion has the coldest January nights (23°) and Philadelphia the hottest July afternoons (87°). Lower Merion’s January low is 24° and its July high 87°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Lower Merion 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 Lower Merion averaged 2.1° warmer than the 1900s. The biggest change is in December (+3.6°). The shift is larger than in 95% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Lower Merion’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. December swings the most: between 1991 and 2020 its average temperature ranged from 29° to 49°. June is the most reliable, staying within 7°.
Common questions about Lower Merion’s climate
What is the coldest month in Lower Merion?
January, with a typical high of 40° and a low of 24°.
What is the hottest month in Lower Merion?
July, with a typical high of 87° and a low of 67°. About 33 days a year reach 90°.
How much snow does Lower Merion get?
About 8 inches in a normal winter, most of it in January.
When is the first frost in Lower Merion?
In half of years the first 32° night comes by October 31, and the last spring frost by April 15.
What is the rainiest month in Lower Merion?
July, with 4.8 inches of rain and melted snow. The year totals 48 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Lower Merion itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Conshohocken, PA (4 mi, snow) and Pennsauken 1n, NJ (14 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.