Glen St. Mary, Florida climate: Normal weather by month, frost dates and records
Glen St. Mary's normal year runs from 40°F January nights to 93°F July afternoons, with 53.2 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 20.4°C, January lows of 4°C, July highs of 34°C, 1,352 mm of precipitation a year.
- NOAA stationGlen St Mary (1 mi W)
- Station IDUSC00083470
- Location30.27°N 82.19°W
- Elevation128 ft (39 m)
- Population504
On October 23, the normal high in Glen St. Mary is 81°F and the normal low 56°F, and the chance of measurable rain or snow is 19%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Glen St. Mary.
- Jan 67° 40°
- Feb 71° 44°
- Mar 76° 48°
- Apr 82° 53°
- May 88° 61°
- Jun 91° 69°
- Jul 93° 71°
- Aug 92° 71°
- Sep 89° 68°
- Oct 83° 59°
- Nov 75° 49°
- Dec 69° 43°
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 Glen St. Mary each month?
July is the warmest month, with normal highs of 93°F; January the coldest, with normal lows of 40°F. The most precipitation falls in June (8.42 in), the least in November (1.93 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 67°F | 40°F | 53.5°F | 3.68 | 8 | <1 | 11 | 10 h 20 min |
| February | 71°F | 44°F | 57.1°F | 3.51 | 8 | <1 | 6 | 11 h 10 min |
| March | 76°F | 48°F | 61.8°F | 3.71 | 8 | <1 | 2 | 12 h |
| April | 82°F | 53°F | 67.5°F | 3.10 | 6 | 1 | <1 | 12 h 50 min |
| May | 88°F | 61°F | 74.2°F | 2.87 | 6 | 8 | <1 | 13 h 40 min |
| June | 91°F | 69°F | 79.8°F | 8.42 | 14 | 17 | <1 | 14 h 10 min |
| July | 93°F | 71°F | 82.0°F | 6.76 | 14 | 23 | <1 | 14 h |
| August | 92°F | 71°F | 81.6°F | 7.12 | 15 | 20 | <1 | 13 h 20 min |
| September | 89°F | 68°F | 78.6°F | 5.84 | 10 | 11 | <1 | 12 h 20 min |
| October | 83°F | 59°F | 70.6°F | 3.65 | 7 | 1 | <1 | 11 h 30 min |
| November | 75°F | 49°F | 62.1°F | 1.93 | 6 | <1 | 2 | 10 h 40 min |
| December | 69°F | 43°F | 56.2°F | 2.63 | 6 | <1 | 7 | 10 h 10 min |
| Year (annual) | 81°F | 56°F | 68.7°F | 53.22 | 106 | 81 | 28 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 19°C | 4°C | 11.9°C | 93 mm |
| February | 21°C | 7°C | 13.9°C | 89 mm |
| March | 24°C | 9°C | 16.6°C | 94 mm |
| April | 28°C | 12°C | 19.7°C | 79 mm |
| May | 31°C | 16°C | 23.4°C | 73 mm |
| June | 33°C | 20°C | 26.6°C | 214 mm |
| July | 34°C | 22°C | 27.8°C | 172 mm |
| August | 33°C | 22°C | 27.6°C | 181 mm |
| September | 32°C | 20°C | 25.9°C | 148 mm |
| October | 28°C | 15°C | 21.4°C | 93 mm |
| November | 24°C | 10°C | 16.7°C | 49 mm |
| December | 21°C | 6°C | 13.4°C | 67 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00083470; 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 Glen St. Mary?
Normal highs sit between 65°F and 85°F in January, February, March, April, October, November and December. Of those, November has the fewest days with rain (6).
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 USC00083470.
When is the last frost in Glen St. Mary?
In Glen St. Mary, the last spring frost (32°F) comes after March 8 in half of years and after March 31 in one year in ten; the first autumn frost comes before December 1 in half of years and before November 9 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
- March 81 year in 10 after March 31; 9 in 10 after February 6
- First autumn frost, half of years before
- December 11 year in 10 before November 9; 9 in 10 before December 28
NOAA puts the median frost-free season at 272 days, and the season without a hard freeze (28°F) at 306 days.
A hard freeze (28°F) comes after February 17 in half of springs and before December 21 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Glen St. Mary in zone 9a in ZIP code 32063, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Glen St. Mary's NOAA station is in zone 9a: the coldest night of a typical year reaches 20°F (17 complete years).
Frost dates for every NOAA station in Florida · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00083470; 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 Glen St. Mary?
In a normal year in Glen St. Mary, 81 days a year reach 90°F (1 of them 100°F or more), 28 nights fall to 32°F or colder and 106 days bring measurable precipitation.
- Days at 90°F or more
- 81a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 28a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 106a normal year
The highest temperature in this station's record (since 1919) is 104°F, on June 5, 1927; the lowest is 7°F, on January 21, 1985.
The wettest calendar year on that record is 1959, with 75.15 in.
Source: NOAA NCEI 1991-2020 annual normals, station USC00083470; records: ACIS (NOAA Regional Climate Centers), station USC00083470. Records use complete months only; a month missing more than three days is left out.
How sunny is Glen St. Mary?
Over a year 79% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Glen St. Mary, 4.7 kWh per square metre a day. May is the sunniest month (83%) and February the cloudiest (74%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 77% | 3.1 |
| February | 74% | 3.8 |
| March | 78% | 4.9 |
| April | 81% | 5.9 |
| May | 83% | 6.4 |
| June | 77% | 6.0 |
| July | 79% | 5.9 |
| August | 77% | 5.4 |
| September | 78% | 4.9 |
| October | 80% | 4.2 |
| November | 81% | 3.5 |
| December | 75% | 2.8 |
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 Glen St. Mary need?
A normal year in Glen St. Mary brings 1,297 heating degree days, 76% fewer than the median U.S. place (5,373), and 2,687 cooling degree days, 3.0 times the median (908). Two months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 7,028 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 370 | 15 |
| February | 239 | 19 |
| March | 154 | 54 |
| April | 52 | 127 |
| May | 6 | 289 |
| June | 0 | 444 |
| July | 0 | 527 |
| August | 0 | 515 |
| September | 0 | 407 |
| October | 28 | 202 |
| November | 149 | 62 |
| December | 300 | 26 |
| Year (annual) | 1,297 | 2,687 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00083470. 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 Glen St. Mary's climate compare?
Glen St. Mary is warmer than 17 of the other 105 places with their own NOAA record in Florida, and wetter than 46. Across the 7,247 U.S. stations with normals, its annual mean of 68.7°F is warmer than 94%.
In the Köppen classification computed from these normals, Glen St. Mary is Cfa: temperate, 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 Glen St. Mary share this climate record?
Macclenny has no NOAA station with 1991-2020 normals of its 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.
- Macclenny, FL8,178 people · 4 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 Glen St. Mary's climate
What is the coldest month in Glen St. Mary?
January, with a normal high of 67°F and a normal low of 40°F. The warmest is July (93°F by day, 71°F at night).
Does it snow in Glen St. Mary?
Rarely: NOAA's normal is no measurable snow a year.
What is the rainiest month in Glen St. Mary?
June, with 8.42 in of precipitation in a normal year; the driest is November with 1.93 in.
What plant hardiness zone is Glen St. Mary in?
The USDA's 2023 map puts Glen St. Mary in zone 9a in ZIP code 32063, the nearest ZIP area. By the same method at Glen St. Mary's NOAA station, the coldest night of a typical year reaches 20°F (17 years, 1991-2020): zone 9a.
How late can frost come in Glen St. Mary?
In half of years the last 32°F night comes after March 8; in one year in ten it comes after March 31. Waiting until March 31 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Florida climateThe statewide normals and every place in the state
- Jackson Whitehouse NOLF, FL19 miles from this station, 68.5°F a year
- Starke, FL24 miles from this station, 70.9°F a year
- Lake City, FL25 miles from this station, 67.2°F a year
- Jacksonville, FL32 miles from this station, 69.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made