Pen Mar climate

Pen Mar Weather in September

NOAA 1991-2020 normals for Catoctin Mtn Park, 8.6 km from Pen Mar

Average highs run from 79°F on September 1 to 70°F on September 30, and lows from 61°F to 53°F. Normal precipitation for the month is 5.32 in over about 12 wet days.

September day by day

The normal high and low for each date, and the record, in °F.

Normal daily high and low temperature at Pen Mar, in °F, with the record for each date.20406080100151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
75°F
Average low
58°F
Precipitation
5.32 in
Record high
92°FSep 1, 2010
Record low
23°FSep 30, 2003
Chance of a freeze
1%
Daylight
13 h 03 min to 11 h 49 min
Cloud cover
55%
Humidity
70%
Dew point
56°F
Wind
6.3 mph

Every day of the month

A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.

DateNormal highNormal lowRecord highRecord lowChance wetChance of snow
Sep 179°F61°F92°F 201046°F 200337%0%
Sep 279°F61°F92°F 201048°F 198737%0%
Sep 379°F61°F88°F 200852°F 197637%0%
Sep 478°F61°F88°F 200844°F 199737%0%
Sep 578°F61°F89°F 197147°F 197438%0%
Sep 678°F60°F90°F 199845°F 198838%0%
Sep 778°F60°F88°F 199839°F 200338%0%
Sep 877°F60°F88°F 200742°F 200338%0%
Sep 977°F60°F87°F 200243°F 198638%0%
Sep 1077°F59°F90°F 198346°F 197538%0%
Sep 1177°F59°F91°F 198342°F 197638%0%
Sep 1276°F59°F89°F 197443°F 199438%0%
Sep 1376°F59°F87°F 199841°F 198538%0%
Sep 1476°F58°F88°F 199838°F 197538%0%
Sep 1575°F58°F87°F 199844°F 200138%0%
Sep 1675°F58°F86°F 199836°F 200338%0%
Sep 1775°F57°F85°F 197039°F 198638%0%
Sep 1874°F57°F82°F 199839°F 199038%0%
Sep 1974°F57°F83°F 198342°F 196938%0%
Sep 2074°F56°F83°F 198341°F 197938%0%
Sep 2173°F56°F84°F 198340°F 200339%0%
Sep 2273°F56°F89°F 201040°F 199939%0%
Sep 2373°F55°F87°F 201038°F 197439%0%
Sep 2472°F55°F90°F 201034°F 197439%0%
Sep 2572°F55°F89°F 200740°F 197439%0%
Sep 2672°F54°F89°F 200742°F 200039%0%
Sep 2771°F54°F86°F 199837°F 198939%0%
Sep 2871°F53°F81°F 199836°F 200339%0%
Sep 2971°F53°F77°F 198028°F 200339%0%
Sep 3070°F53°F85°F 198623°F 200338%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Pen Mar, in percent, and of at least 0.1 inch of snowfall.0102030401102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (EDT).

September 1
sunrise 6:38 AM, sunset 7:41 PM
September 30
sunrise 7:05 AM, sunset 6:54 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00181530 (Catoctin Mtn Park), public domain. Records: NOAA GHCN-Daily, station USC00181530, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.