Photo: Legohead · CC BY-SA 3.0St. Marys’ winters are milder and less snowy than most of the U.S.
A typical July afternoon reaches 91°, a January night drops to 43°, and snow is almost unheard of.
A year in St. Marys at a glance
Each month’s typical high and low, and what it brings.
What stands out about St. Marys’ climate
Compared with towns across the U.S., with St. Marys’ place in Georgia beside it.
What a year in St. Marys feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 299 frost-free days a year
In half of years the last 32° night comes by February 19 and the first by December 14. Frost and day counts come from NOAA’s station at Brunswick 23 S, GA, 8 miles from the town’s center, at about the same height.
The 2023 USDA map puts St. Marys’ center in zone 9a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 24°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 51 inches of rain a year
August is the wettest month and November the driest. Rain falls on about 114 days a year. Snow is rare: about 0.0" in a normal year at Fernandina Beach, FL, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in St. Marys
37% of the work is heating, so air conditioning is the bigger bill. Months averaging under 55° run from January.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Brunswick 23 S, GA.
Living with St. Marys’ climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
299 frost-free days in zone 9a. The last frost comes by Feb 19 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Dec 14.
Months with highs of 62–84° and lows of 40° or more: January, February, March, April, October, November and December. 4.2 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in St. Marys from natural hazards, hurricanes are the largest share (50%); heat waves, cold waves, winter storms and ice storms together are 4%. Normals are averages; the hazards page covers the extremes.
Natural hazards →St. Marys and similar climates
TownRatings has no climate map of the towns around St. Marys yet.
Climates most like St. Marys’, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| St. Marys, GA | 43° | 91° | 51" | 0.0" |
| Lake Jackson, TX | 45° | 92° | 50" | 0.0" |
| Sugarmill Woods, FL | 46° | 91° | 52" | 0.0" |
| Mount Pleasant, SC | 41° | 90° | 50" | 0.3" |
| Headland, AL | 39° | 91° | 56" | 0.1" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in St. Marys averaged 1.3° warmer than the 1900s. The biggest change is in December (+2.2°).
A smaller shift than in 51% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How St. Marys compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with St. Marys’ place among Georgia’s.
St. Marys weather by month
Highs, lows and precipitation from NOAA’s grid at St. Marys’ center; snow, wet days and snow on the ground from Fernandina Beach, FL. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 64° | 43° | 3.4" | 0.0" | 9 | 0 | 48° – 60° |
| February | 67° | 46° | 3.0" | 0.0" | 9 | 0 | 48° – 65° |
| March | 72° | 51° | 3.4" | 0.0" | 8 | 0 | 55° – 68° |
| April | 78° | 57° | 3.0" | 0.0" | 7 | 0 | 63° – 72° |
| May | 84° | 65° | 3.1" | 0.0" | 7 | 0 | 71° – 78° |
| June | 89° | 71° | 6.6" | 0.0" | 13 | 0 | 76° – 84° |
| July | 91° | 73° | 5.6" | 0.0" | 13 | 0 | 81° – 85° |
| August | 90° | 73° | 6.9" | 0.0" | 13 | 0 | 80° – 84° |
| September | 86° | 71° | 6.4" | 0.0" | 13 | 0 | 76° – 82° |
| October | 80° | 62° | 4.4" | 0.0" | 8 | 0 | 67° – 76° |
| November | 72° | 52° | 2.1" | 0.0" | 7 | 0 | 57° – 68° |
| December | 66° | 46° | 2.9" | 0.0" | 9 | 0 | 46° – 66° |
| Year | 78° | 59° | 50.7" | 0.0" | 114 | 0 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 46° to 66°. July is the most reliable, staying within 4°.
Where St. Marys’ numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at St. Marys’ center.
- Snow: Fernandina Beach, FL.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Brunswick 23 S, GA, 8 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about St. Marys’ climate
What is the weather like in St. Marys?
A typical July afternoon reaches 91°, a January night drops to 43°, and snow is almost unheard of. Milder January nights than 92% of U.S. towns; hotter July afternoons than 84% of U.S. towns.
How cold does it get in St. Marys in winter?
January nights average 43°. About 12 nights a year reach 32° or below. In the coldest January of the last 30 years the month averaged 48°.
How much snow does St. Marys get?
About 0.0 inches in a normal winter at Fernandina Beach, FL, so most winters see none.
How hot does it get in St. Marys?
July, with a typical high of 91° and a low of 73°. About 40 days a year reach 90° (Brunswick 23 S, GA).
When is the first and last frost in St. Marys?
In half of years the last spring frost (32°) comes by February 19 and the first fall frost by December 14, about 299 frost-free days, at Brunswick 23 S, GA.
What growing zone is St. Marys in?
Zone 9a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 24°.
What is the best time of year to visit St. Marys?
By one simple rule (highs of 62–84° and lows of 40° or more), January, February, March, April, October, November and December. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is St. Marys getting warmer?
Yes: 1991–2020 averaged 1.3° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 51% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in St. Marys.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.