West Mifflin has chilly winters and pleasant summers. A typical July afternoon reaches 84°, a January night drops to 22°, and about 21 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normalsUpdated once a decade
☀️
July high
84°
1688th hottest of 3,547 Pennsylvania towns
❄️
January low
22°
797th mildest of 3,547 Pennsylvania towns
💧
Rain + melted snow
42 in
601st driest of 3,547 Pennsylvania towns
🌨️
Snow a winter
21 in
466th least snowy of 3,541 Pennsylvania towns
A normal year
What a year in West Mifflin feels like
❄️
Winter
40° / 24°
Typical high / low · 8 days with an inch or more of snow
🌷
Spring
62° / 40°
Typical high / low · Last frost around Apr 18
☀️
Summer
82° / 60°
Typical high / low · 8 days reach 90° in a normal year
🍂
Fall
64° / 44°
Typical high / low · First frost around Oct 28
10°
20°
40°
50°
60°
70°
80°
90°
100°
32°
38°
22°
41°
24°
50°
31°
63°
40°
73°
49°
80°
58°
84°
62°
82°
61°
76°
54°
65°
43°
52°
34°
42°
27°
JanJFebFMarMAprAMayMJunJJulJAugASepSOctONovNDecD
32°, freezingBar runs from the typical overnight low up to the afternoon high
Best months to be outsideMayJunJulAugSepOctHighs of 62–84° and lows of 40° or more
Month by month
West Mifflin 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
38°
22°
3.0"
5.7"
15
9
22° – 39°
February
41°
24°
2.6"
7.2"
12
7
19° – 41°
March
50°
31°
3.3"
4.6"
13
3
34° – 52°
April
63°
40°
3.5"
0.1"
14
0
46° – 56°
May
73°
49°
4.0"
0
14
0
54° – 68°
June
80°
58°
4.5"
0
13
0
65° – 71°
July
84°
62°
4.4"
0
11
0
69° – 77°
August
82°
61°
3.8"
0
10
0
67° – 77°
September
76°
54°
3.5"
0
10
0
61° – 70°
October
65°
43°
3.0"
0
12
0
50° – 60°
November
52°
34°
2.9"
0.5"
12
1
37° – 48°
December
42°
27°
3.2"
3.3"
13
5
24° – 45°
Year
62°
42°
41.6"
21.4"
147
24
“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 & snow
Rain and snow in West Mifflin
West Mifflin 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 147 days a year. Snow covers the ground about 24 days of the year.
💧
42 in
Rain + melted snow a year
More rain than 57% of U.S. towns
❄️
21 in
Snow in a normal winter
Less snow than 55% of U.S. towns
⛄
24 days
With 1"+ of snow on the ground
Fewer than 54% of U.S. towns
Rain + melted snow by month
Inches of water
4.5"
JFMAMJJASOND
Snowfall by month
Inches of snow
7.2"
JFMAMJJASOND
Frost & the growing season
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.
🌱 Apr 18
🍂 Oct 28
193 frost-free days
JFMAMJJASOND
🥶
106
nights at or below 32° in a normal year
🧊
1
nights below 0° in a normal year
🔥
8
days that reach 90° in a normal year
Freezing nights by month
Average nights at or below 32°
JFMAMJJASOND
90° days by month
Average days at 90° or more
JFMAMJJASOND
Heating & cooling
Heating and cooling a home in West Mifflin
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In West Mifflin, 87% of that work is heating and 13% is cooling, so the furnace matters far more than the air conditioner.
🔥
5,407 heating degree daysLess heating than 58% of U.S. towns
❄️
826 cooling degree daysLess cooling than 52% of U.S. towns
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.
Around West Mifflin
West Mifflin and its neighbors
West Mifflin borders 12 towns with climate data. January nights across them vary by 0.5°. Dravosburg has the coldest January nights (22°) and Pittsburgh the hottest July afternoons (85°). West Mifflin’s January low is 22° and its July high 84°.
Compared with every U.S. town and city on TownTapestry, each counted once.
Then and now
Warmer than it used to be
+1.0°1991–2020 average vs. the 20th century (1901–2000)
The last 30 years in West Mifflin averaged 1.0° warmer than the 1900s. The biggest change is in December (+2.2°). The shift is smaller than in 67% of U.S. towns.
❄️ Winter+1.7°now 32°, was 30°
🌷 Spring+1.2°now 51°, was 50°
☀️ Summer+0.5°now 71°, was 71°
🍂 Fall+0.8°now 54°, was 53°
Change by month1991–2020 average minus 1901–2000 average, at West Mifflin’s spot on NOAA’s grid
+0.2°
+2.2°
JanJFebFMarMAprAMayMJunJJulJAugASepSOctONovNDecD
Year to year
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 6°.
10°
20°
30°
40°
50°
60°
70°
80°
90°
JanJFebFMarMAprAMayMJunJJulJAugASepSOctONovNDecD
Coldest to warmest month in 30 yearsNormal
Questions
Common questions about West Mifflin’s climate
What is the coldest month in West Mifflin?
January, with a typical high of 38° and a low of 22°.
What is the hottest month in West Mifflin?
July, with a typical high of 84° and a low of 62°. About 8 days a year reach 90°.
How much snow does West Mifflin get?
About 21 inches in a normal winter, most of it in February.
When is the first frost in West Mifflin?
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 West Mifflin?
June, with 4.5 inches of rain and melted snow. The year totals 42 inches.
📍Temperatures and rainfall come from NOAA’s gridded climate normals for West Mifflin itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Donora 1 Sw, PA (14 mi, snow) and Pittsburgh Allegheny Co Airport, PA (1 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.