Hourly Weather Forecast - Mercersburg, PA

12 AM
29°F
10%
1mph
SSE
Mostly Cloudy
Humidity
62%
Feels like
29°F
Dew Point
18°F
1 AM
29°F
10%
1mph
SSE
Partly Cloudy
Humidity
62%
Feels like
29°F
Dew Point
18°F
2 AM
29°F
20%
1mph
SSE
Mostly Cloudy
Humidity
64%
Feels like
29°F
Dew Point
19°F
3 AM
29°F
20%
1mph
SSE
Mostly Cloudy
Humidity
66%
Feels like
29°F
Dew Point
19°F
4 AM
29°F
20%
1mph
SSE
Cloudy
Humidity
68%
Feels like
29°F
Dew Point
20°F
5 AM
29°F
20%
1mph
SSE
Cloudy
Humidity
70%
Feels like
29°F
Dew Point
20°F
6 AM
29°F
20%
1mph
S
Cloudy
Humidity
73%
Feels like
29°F
Dew Point
21°F
7 AM
29°F
30%
1mph
S
30% Chance of Flurries
Humidity
72%
Feels like
29°F
Dew Point
22°F
7:30 AM
8 AM
31°F
30%
2mph
S
30% Chance of Flurries
Humidity
73%
Feels like
31°F
Dew Point
23°F
9 AM
33°F
30%
2mph
S
30% Chance of Flurries
Humidity
71%
Feels like
33°F
Dew Point
25°F
10 AM
35°F
30%
3mph
S
30% Chance of Flurries
Humidity
68%
Feels like
32°F
Dew Point
25°F

Rainfall and Snowfall Totals Through Thursday

Pineapple Express Slams Northwestern U.S.

The atmospheric river this week will keep buffeting the Pacific Northwest with heavy rain, snow, and high winds.

Wednesday's Weather Outlook

Today's Weather Outlook

How to Measure Snow via NWS

How To Measure Snow

Weekly Drought Map for December 11, 2025

Hit-or-Miss Precipitation Leads to Mixed Drought Results

A person standing in a snowy forest with their back to the camera. They are bundled up in a white hat and a brown jacket. (Image by StockSnap from Pixabay)

Common Cold Weather Illnesses

A strong cold-air-damming event from March 20, 2018.

Cold Air Damming - Cause And Effects

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