Hanover, Pennsylvania climate: Normal weather by month, frost dates and records
Hanover's normal year runs from 21°F January nights to 85°F July afternoons, with 44.1 inches of precipitation and 28 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.4°C, January lows of −6°C, July highs of 30°C, 1,120 mm of precipitation a year.
- NOAA stationHanover (4 mi SW)
- Station IDUSC00363665
- Location39.77°N 77.03°W
- Elevation558 ft (170 m)
- From the center4 miles
- Population16,728
On October 23, the normal high in Hanover is 63°F and the normal low 40°F, and the chance of measurable rain or snow is 32%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Hanover.
- Jan 39° 21°
- Feb 42° 23°
- Mar 50° 30°
- Apr 63° 40°
- May 72° 50°
- Jun 81° 60°
- Jul 85° 64°
- Aug 84° 62°
- Sep 77° 54°
- Oct 66° 43°
- Nov 54° 33°
- Dec 44° 26°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Hanover each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 21°F. The most precipitation falls in September (4.83 in), the least in February (2.59 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 39°F | 21°F | 30.2°F | 3.02 | 8.0 | 10 | <1 | 27 | 9 h 40 min |
| February | 42°F | 23°F | 32.4°F | 2.59 | 9.7 | 9 | <1 | 24 | 10 h 40 min |
| March | 50°F | 30°F | 40.1°F | 3.71 | 5.2 | 11 | <1 | 20 | 11 h 50 min |
| April | 63°F | 40°F | 51.3°F | 3.73 | 0.1 | 13 | <1 | 6 | 13 h 10 min |
| May | 72°F | 50°F | 61.2°F | 3.88 | 0.0 | 14 | 1 | 1 | 14 h 20 min |
| June | 81°F | 60°F | 70.3°F | 3.68 | 0.0 | 12 | 3 | <1 | 15 h |
| July | 85°F | 64°F | 74.6°F | 4.31 | 0.0 | 11 | 8 | <1 | 14 h 40 min |
| August | 84°F | 62°F | 72.8°F | 3.86 | 0.0 | 10 | 5 | <1 | 13 h 50 min |
| September | 77°F | 54°F | 65.6°F | 4.83 | 0.0 | 10 | 2 | <1 | 12 h 30 min |
| October | 66°F | 43°F | 54.1°F | 3.86 | 0.1 | 10 | <1 | 4 | 11 h 10 min |
| November | 54°F | 33°F | 43.6°F | 3.13 | 0.6 | 9 | <1 | 16 | 10 h |
| December | 44°F | 26°F | 34.7°F | 3.51 | 4.5 | 10 | <1 | 25 | 9 h 20 min |
| Year (annual) | 63°F | 42°F | 52.6°F | 44.11 | 28.2 | 128 | 18 | 122 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 4°C | −6°C | −1.0°C | 77 mm | 20 cm |
| February | 6°C | −5°C | 0.2°C | 66 mm | 25 cm |
| March | 10°C | −1°C | 4.5°C | 94 mm | 13 cm |
| April | 17°C | 4°C | 10.7°C | 95 mm | 0 cm |
| May | 22°C | 10°C | 16.2°C | 99 mm | 0 cm |
| June | 27°C | 15°C | 21.3°C | 93 mm | 0 cm |
| July | 30°C | 18°C | 23.7°C | 109 mm | 0 cm |
| August | 29°C | 17°C | 22.7°C | 98 mm | 0 cm |
| September | 25°C | 12°C | 18.7°C | 123 mm | 0 cm |
| October | 19°C | 6°C | 12.3°C | 98 mm | 0 cm |
| November | 12°C | 1°C | 6.4°C | 80 mm | 2 cm |
| December | 7°C | −4°C | 1.5°C | 89 mm | 11 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00363665; 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.
When is the best weather to visit Hanover?
Normal highs sit between 65°F and 85°F in May, June, August, September and October. Of those, September has the fewest days with rain (10).
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 USC00363665.
When is the last frost in Hanover?
In Hanover, the last spring frost (32°F) comes after April 24 in half of years and after May 11 in one year in ten; the first autumn frost comes before October 20 in half of years and before October 6 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 241 year in 10 after May 11; 9 in 10 after April 9
- First autumn frost, half of years before
- October 201 year in 10 before October 6; 9 in 10 before November 2
NOAA puts the median frost-free season at 177 days, and the season without a hard freeze (28°F) at 203 days.
A hard freeze (28°F) comes after April 9 in half of springs and before October 31 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Hanover in zone 7a in ZIP code 17331, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Hanover's NOAA station is in zone 6b: the coldest night of a typical year reaches −1°F (25 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Pennsylvania · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00363665; 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 in Hanover?
In a normal year in Hanover, 18 days a year reach 90°F, 122 nights fall to 32°F or colder and 128 days bring measurable precipitation.
- Days at 90°F or more
- 18a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 122a normal year
- Days that stay below freezing
- 19high of 32°F or less
- Days with 0.01 inch of precipitation
- 128a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1993) is 102°F, on July 23, 2011; the lowest is −16°F, on February 5, 1996.
The wettest calendar year on that record is 2018, with 62.75 in; the snowiest season is 2009–10, with 78.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00363665; records: ACIS (NOAA Regional Climate Centers), station USC00363665. Records use complete months only; a month missing more than three days is left out.
How sunny is Hanover?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Hanover, 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 much heating and cooling does Hanover need?
A normal year in Hanover brings 5,397 heating degree days, 0% more than the median U.S. place (5,373), and 904 cooling degree days, 0% 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 3,289 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,077 | 0 |
| February | 913 | 0 |
| March | 771 | 1 |
| April | 422 | 11 |
| May | 173 | 55 |
| June | 27 | 185 |
| July | 2 | 298 |
| August | 6 | 246 |
| September | 77 | 97 |
| October | 348 | 12 |
| November | 642 | 0 |
| December | 939 | 0 |
| Year (annual) | 5,397 | 904 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00363665. 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 Hanover's climate compare?
Hanover is warmer than 89 of the other 107 places with their own NOAA record in Pennsylvania, and wetter than 54. Across the 7,247 U.S. stations with normals, its annual mean of 52.6°F is warmer than 52%.
In the Köppen classification computed from these normals, Hanover 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 Hanover share this climate record?
9 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.
- Westminster, MD20,662 people · 13 mi S
- Taneytown, MD8,293 people · 11 mi SW
- Hampstead, MD6,288 people · 14 mi SE
- Manchester, MD5,440 people · 11 mi SE
- McSherrystown, PA3,161 people · 2 mi N
- New Oxford, PA1,921 people · 7 mi N
- New Windsor, MD1,758 people · 16 mi S
- Union Bridge, MD946 people · 16 mi SW
- Midway, PA737 people · 3 mi NE
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 Hanover's climate
What is the coldest month in Hanover?
January, with a normal high of 39°F and a normal low of 21°F. The warmest is July (85°F by day, 64°F at night).
Does it snow in Hanover?
Yes: 28 inches in a normal year, falling on 14 days with 0.1 inch or more, the most in February (9.7 inches).
What is the rainiest month in Hanover?
September, with 4.83 in of precipitation in a normal year; the driest is February with 2.59 in.
What plant hardiness zone is Hanover in?
The USDA's 2023 map puts Hanover in zone 7a in ZIP code 17331, the nearest ZIP area. By the same method at Hanover's NOAA station, the coldest night of a typical year reaches −1°F (25 years, 1991-2020): zone 6b.
How late can frost come in Hanover?
In half of years the last 32°F night comes after April 24; in one year in ten it comes after May 11. Waiting until May 11 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Hanover in OctoberThis month day by day, its records and recent years
- Pennsylvania climateThe statewide normals and every place in the state
- Eisenhower National Historic Site, PA11 miles from this station, 52.8°F a year
- Millers (4 mi NE), MD12 miles from this station, 53.6°F a year
- York, PA13 miles from this station, 52.4°F a year
- Emmitsburg, MD15 miles from this station, 53.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made