Glassboro, New Jersey climate: Normal weather by month, frost dates and records
Glassboro's normal year runs from 25°F January nights to 87°F July afternoons. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.7°C, January lows of −4°C, July highs of 30°C.
- NOAA stationGlassboro (2 mi NE)
- Station IDUSC00283291
- Location39.74°N 75.10°W
- Elevation100 ft (31 m)
- From the center3 miles
- Population24,322
On October 23, the normal high in Glassboro is 64°F and the normal low 43°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Glassboro.
- Jan 41° 25°
- Feb 44° 26°
- Mar 52° 33°
- Apr 64° 41°
- May 73° 52°
- Jun 82° 62°
- Jul 87° 67°
- Aug 85° 66°
- Sep 79° 60°
- Oct 67° 46°
- Nov 55° 37°
- Dec 46° 30°
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 Glassboro each month?
July is the warmest month, with normal highs of 87°F; January the coldest, with normal lows of 25°F.
| Month | High | Low | Mean | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|
| January | 41°F | 25°F | 33.2°F | – | <1 | 25 | 9 h 40 min |
| February | 44°F | 26°F | 35.1°F | – | <1 | 21 | 10 h 40 min |
| March | 52°F | 33°F | 42.6°F | – | <1 | 16 | 11 h 50 min |
| April | 64°F | 41°F | 52.5°F | – | <1 | 3 | 13 h 10 min |
| May | 73°F | 52°F | 62.3°F | – | 1 | <1 | 14 h 20 min |
| June | 82°F | 62°F | 71.9°F | – | 5 | <1 | 15 h |
| July | 87°F | 67°F | 77.0°F | – | 9 | <1 | 14 h 40 min |
| August | 85°F | 66°F | 75.2°F | – | 4 | <1 | 13 h 50 min |
| September | 79°F | 60°F | 69.1°F | – | <1 | <1 | 12 h 30 min |
| October | 67°F | 46°F | 56.3°F | – | <1 | 1 | 11 h 10 min |
| November | 55°F | 37°F | 45.8°F | – | <1 | 13 | 10 h |
| December | 46°F | 30°F | 38.0°F | – | <1 | 21 | 9 h 20 min |
| Year (annual) | 65°F | 45°F | 54.9°F | – | 20 | 100 |
The same normals in °C and millimetres
| Month | High | Low | Mean |
|---|---|---|---|
| January | 5°C | −4°C | 0.7°C |
| February | 7°C | −3°C | 1.7°C |
| March | 11°C | 1°C | 5.9°C |
| April | 18°C | 5°C | 11.4°C |
| May | 23°C | 11°C | 16.8°C |
| June | 28°C | 17°C | 22.2°C |
| July | 30°C | 20°C | 25.0°C |
| August | 29°C | 19°C | 24.0°C |
| September | 26°C | 15°C | 20.6°C |
| October | 19°C | 8°C | 13.5°C |
| November | 13°C | 3°C | 7.7°C |
| December | 8°C | −1°C | 3.3°C |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Philadelphia (12 miles away), gets 23 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00283291; 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 Glassboro?
Normal highs sit between 65°F and 85°F in May, June, August, September and October.
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 USC00283291.
When is the last frost in Glassboro?
In Glassboro, the last spring frost (32°F) comes after April 8 in half of years and after April 22 in one year in ten; the first autumn frost comes before November 1 in half of years and before October 18 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 81 year in 10 after April 22; 9 in 10 after March 27
- First autumn frost, half of years before
- November 11 year in 10 before October 18; 9 in 10 before November 15
NOAA puts the median frost-free season at 205 days, and the season without a hard freeze (28°F) at 229 days.
A hard freeze (28°F) comes after March 27 in half of springs and before November 11 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Glassboro in zone 7b in ZIP code 08028.
Frost dates for every NOAA station in New Jersey · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00283291; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. 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 Glassboro?
In a normal year in Glassboro, 20 days a year reach 90°F and 100 nights fall to 32°F or colder.
- Days at 90°F or more
- 20a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 100a normal year
- Days that stay below freezing
- 13high of 32°F or less
The highest temperature in this station's record (since 1963) is 104°F, on July 4, 1966; the lowest is −6°F, on January 20, 1994.
The wettest calendar year on that record is 1975, with 63.41 in; the snowiest season is 1982–83, with 18.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00283291; records: ACIS (NOAA Regional Climate Centers), station USC00283291. Records use complete months only; a month missing more than three days is left out.
How sunny is Glassboro?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Glassboro, 4.1 kWh per square metre a day. July is the sunniest month (82%) and December the cloudiest (68%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 68% | 2.0 |
| February | 71% | 2.9 |
| March | 69% | 3.8 |
| April | 73% | 5.0 |
| May | 72% | 5.6 |
| June | 78% | 6.2 |
| July | 82% | 6.2 |
| August | 80% | 5.4 |
| September | 77% | 4.4 |
| October | 73% | 3.2 |
| November | 74% | 2.3 |
| December | 68% | 1.8 |
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 Glassboro need?
A normal year in Glassboro brings 4,809 heating degree days, 10% fewer than the median U.S. place (5,373), and 1,168 cooling degree days, 29% more than the median (908). Six months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,696 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 985 | 0 |
| February | 836 | 0 |
| March | 697 | 1 |
| April | 386 | 11 |
| May | 146 | 62 |
| June | 18 | 225 |
| July | 1 | 372 |
| August | 1 | 316 |
| September | 38 | 162 |
| October | 289 | 19 |
| November | 575 | 1 |
| December | 838 | 0 |
| Year (annual) | 4,809 | 1,168 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00283291. 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 Glassboro's climate compare?
Glassboro is warmer than 23 of the other 32 places with their own NOAA record in New Jersey. Across the 7,247 U.S. stations with normals, its annual mean of 54.9°F is warmer than 60%.
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers.
Which places near Glassboro share this climate record?
3 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.
- Sicklerville, NJ44,500 people · 6 mi E
- Williamstown, NJ14,855 people · 8 mi SE
- Clayton, NJ9,016 people · 5 mi S
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 Glassboro's climate
What is the coldest month in Glassboro?
January, with a normal high of 41°F and a normal low of 25°F. The warmest is July (87°F by day, 67°F at night).
Does it snow in Glassboro?
Yes. NOAA publishes no 1991-2020 snowfall normal for Glassboro's NOAA station; the nearest record that keeps one, Philadelphia (12 miles away), records 23 inches of snow in a normal year.
What plant hardiness zone is Glassboro in?
The USDA's 2023 map puts Glassboro in zone 7b in ZIP code 08028.
How late can frost come in Glassboro?
In half of years the last 32°F night comes after April 8; in one year in ten it comes after April 22. Waiting until April 22 leaves about a one-in-ten chance of a later frost.
Nearby and next
- New Jersey climateThe statewide normals and every place in the state
- Philadelphia, PA12 miles from this station, 56.3°F a year
- Woodstown, NJ14 miles from this station, 55.9°F a year
- Phila Franklin Inst, PA16 miles from this station, 57.7°F a year
- Moorestown-Lenola, NJ16 miles from this station, 55.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made