Catoctin Mountain Park, Maryland climate: Climate normals at a NOAA weather station
Catoctin Mountain Park's normal year runs from 23°F January nights to 84°F July afternoons, with 48.6 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.9°C, January lows of −5°C, July highs of 29°C, 1,235 mm of precipitation a year.
- NOAA stationCatoctin Mountain Park
- Station IDUSC00181530
- Location39.65°N 77.48°W
- Elevation1,610 ft (491 m)
On October 23, the normal high in Catoctin Mountain Park is 63°F and the normal low 44°F, and the chance of measurable rain or snow is 35%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Catoctin Mountain Park.
- Jan 39° 23°
- Feb 42° 25°
- Mar 52° 31°
- Apr 65° 42°
- May 73° 52°
- Jun 80° 60°
- Jul 84° 65°
- Aug 81° 63°
- Sep 75° 58°
- Oct 65° 46°
- Nov 54° 36°
- Dec 43° 28°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Catoctin Mountain Park each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 23°F. The most precipitation falls in September (5.32 in), the least in February (3.02 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 39°F | 23°F | 31.0°F | 3.77 | 10 | <1 | 26 | 9 h 40 min |
| February | 42°F | 25°F | 33.4°F | 3.02 | 9 | <1 | 23 | 10 h 40 min |
| March | 52°F | 31°F | 41.6°F | 4.43 | 12 | <1 | 17 | 11 h 50 min |
| April | 65°F | 42°F | 53.8°F | 4.02 | 12 | <1 | 5 | 13 h 10 min |
| May | 73°F | 52°F | 62.6°F | 4.88 | 14 | <1 | <1 | 14 h 20 min |
| June | 80°F | 60°F | 70.0°F | 4.21 | 12 | 1 | <1 | 15 h |
| July | 84°F | 65°F | 74.1°F | 3.71 | 12 | 3 | <1 | 14 h 40 min |
| August | 81°F | 63°F | 72.3°F | 4.03 | 12 | 2 | <1 | 13 h 50 min |
| September | 75°F | 58°F | 66.2°F | 5.32 | 12 | <1 | <1 | 12 h 30 min |
| October | 65°F | 46°F | 55.6°F | 4.09 | 11 | <1 | 2 | 11 h 10 min |
| November | 54°F | 36°F | 44.7°F | 3.66 | 11 | <1 | 11 | 10 h |
| December | 43°F | 28°F | 35.6°F | 3.49 | 10 | <1 | 23 | 9 h 20 min |
| Year (annual) | 63°F | 44°F | 53.4°F | 48.63 | 136 | 7 | 106 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 4°C | −5°C | −0.6°C | 96 mm |
| February | 6°C | −4°C | 0.8°C | 77 mm |
| March | 11°C | 0°C | 5.3°C | 113 mm |
| April | 18°C | 6°C | 12.1°C | 102 mm |
| May | 23°C | 11°C | 17.0°C | 124 mm |
| June | 27°C | 16°C | 21.1°C | 107 mm |
| July | 29°C | 18°C | 23.4°C | 94 mm |
| August | 27°C | 17°C | 22.4°C | 102 mm |
| September | 24°C | 14°C | 19.0°C | 135 mm |
| October | 18°C | 8°C | 13.1°C | 104 mm |
| November | 12°C | 2°C | 7.1°C | 93 mm |
| December | 6°C | −2°C | 2.0°C | 89 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Emmitsburg (11 miles away), gets 28 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00181530; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
Which months are mildest at Catoctin Mountain Park?
Normal highs sit between 65°F and 85°F in April, May, June, July, August, September and October. Of those, October has the fewest days with rain (11).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00181530.
When is the last frost at Catoctin Mountain Park?
In Catoctin Mountain Park, the last spring frost (32°F) comes after April 14 in half of years and after April 30 in one year in ten; the first autumn frost comes before October 30 in half of years and before October 14 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 141 year in 10 after April 30; 9 in 10 after April 2
- First autumn frost, half of years before
- October 301 year in 10 before October 14; 9 in 10 before November 11
NOAA puts the median frost-free season at 197 days, and the season without a hard freeze (28°F) at 218 days.
A hard freeze (28°F) comes after April 4 in half of springs and before November 8 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Catoctin Mountain Park in zone 7a in ZIP code 21780, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 7a: the coldest night of a typical year reaches 1°F (16 complete years).
Frost dates for every NOAA station in Maryland · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00181530; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get at Catoctin Mountain Park?
In a normal year in Catoctin Mountain Park, 7 days a year reach 90°F, 106 nights fall to 32°F or colder and 136 days bring measurable precipitation.
- Days at 90°F or more
- 7a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 106a normal year
- Days that stay below freezing
- 23high of 32°F or less
- Days with 0.01 inch of precipitation
- 136a normal year
The highest temperature in this station's record (since 1968) is 98°F, on July 14, 1973; the lowest is −18°F, on January 19, 1994.
The wettest calendar year on that record is 2003, with 75.13 in; the snowiest season is 1969–70, with 62.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00181530; records: ACIS (NOAA Regional Climate Centers), station USC00181530. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Catoctin Mountain Park?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds at Catoctin Mountain Park, 4.0 kWh per square metre a day. July is the sunniest month (79%) and January the cloudiest (65%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 65% | 2.0 |
| February | 68% | 2.8 |
| March | 68% | 3.8 |
| April | 71% | 4.9 |
| May | 71% | 5.4 |
| June | 77% | 6.1 |
| July | 79% | 6.0 |
| August | 78% | 5.3 |
| September | 75% | 4.3 |
| October | 72% | 3.1 |
| November | 72% | 2.3 |
| December | 66% | 1.7 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How many heating and cooling degree days does Catoctin Mountain Park record?
A normal year at Catoctin Mountain Park brings 5,088 heating degree days, 5% fewer than the median U.S. place (5,373), and 898 cooling degree days, 1% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,429 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,055 | 0 |
| February | 883 | 0 |
| March | 727 | 2 |
| April | 358 | 20 |
| May | 139 | 65 |
| June | 26 | 176 |
| July | 2 | 285 |
| August | 6 | 232 |
| September | 64 | 99 |
| October | 307 | 17 |
| November | 610 | 1 |
| December | 911 | 0 |
| Year (annual) | 5,088 | 898 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00181530. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
How does Catoctin Mountain Park's climate compare?
Catoctin Mountain Park is warmer than 5 of the 26 places with their own NOAA record in Maryland, and wetter than 21. Across the 7,247 U.S. stations with normals, its annual mean of 53.4°F is warmer than 55%.
In the Köppen classification computed from these normals, Catoctin Mountain Park is Dfa: continental, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Catoctin Mountain Park share this climate record?
4 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Thurmont, MD6,308 people · 4 mi SE
- Blue Ridge Summit, PA1,016 people · 6 mi N
- Lewistown, MD329 people · 8 mi SE
- Graceham, MD192 people · 5 mi E
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Catoctin Mountain Park's climate
What is the coldest month at Catoctin Mountain Park?
January, with a normal high of 39°F and a normal low of 23°F. The warmest is July (84°F by day, 65°F at night).
Does it snow at Catoctin Mountain Park?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, Emmitsburg (11 miles away), records 28 inches of snow in a normal year.
What is the rainiest month at Catoctin Mountain Park?
September, with 5.32 in of precipitation in a normal year; the driest is February with 3.02 in.
What plant hardiness zone is Catoctin Mountain Park in?
The USDA's 2023 map puts Catoctin Mountain Park in zone 7a in ZIP code 21780, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches 1°F (16 years, 1991-2020): zone 7a.
How late can frost come at Catoctin Mountain Park?
In half of years the last 32°F night comes after April 14; in one year in ten it comes after April 30. Waiting until April 30 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Maryland climateThe statewide normals and every place in the state
- Smithsburg, MD6 miles from this station, 52.3°F a year
- Emmitsburg, MD11 miles from this station, 53.0°F a year
- Hagerstown, MD14 miles from this station, 55.4°F a year
- South Mountain, PA14 miles from this station, 50.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made