January in San Leon stays gentler than in 95% of U.S. towns
On a normal July day the thermometer tops out near 90°. Precipitation is plentiful here, more than falls on 93% of U.S. towns. February has warmed most since 1901–2000, part of a 1.4° rise. Seedlings are safe outdoors from about January 31, with the first autumn frost due around December 14.
A year in San Leon at a glance
Each month’s typical high and low, and what it brings.
What stands out about San Leon’s climate
Compared with towns across the U.S., with San Leon’s place in Texas beside it.
What a year in San Leon feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 317 frost-free days a year
In half of years the last 32° night comes by January 31 and the first by December 14. Frost and day counts come from NOAA’s station at Houston Nwso, TX, 9 miles from the town’s center, at about the same height.
The 2023 USDA map puts San Leon’s center in zone 10a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 30°. 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 54 inches of rain a year
September is the wettest month and February the driest. Rain falls on about 111 days a year. Snow is rare: about 0.2" in a normal year at Houston Nwso, TX, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in San Leon
26% 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 Houston Nwso, TX.
Living with San Leon’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
317 frost-free days in zone 10a. The last frost comes by Jan 31 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, May, October, November and December. 1.5 miles of trails are waiting.
Parks & trails →Cold waves are 34% of the yearly building losses FEMA expects in San Leon from natural hazards, the largest share. Normals are averages; the hazards page covers the extremes.
Natural hazards →San Leon and its neighbors
Every town next door is within a degree of San Leon in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like San Leon’s, 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 |
|---|---|---|---|---|
| San Leon, TX | 46° | 90° | 54" | 0.2" |
| St. Augustine, FL | 47° | 90° | 53" | 0.0" |
| St. Marys, GA | 43° | 91° | 51" | 0.0" |
| Patterson, LA | 44° | 90° | 60" | 0.0" |
| Mount Pleasant, SC | 41° | 90° | 50" | 0.3" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in San Leon averaged 1.4° warmer than the 1900s. The biggest change is in February (+2.5°).
A bigger shift than in 54% 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 San Leon compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with San Leon’s place among Texas’.
San Leon weather by month
Highs, lows and precipitation from NOAA’s grid at San Leon’s center; snow, wet days and snow on the ground from Houston Nwso, TX. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 62° | 46° | 4.5" | 0.0" | 10 | 0 | 49° – 61° |
| February | 65° | 51° | 2.9" | 0.0" | 9 | 0 | 49° – 66° |
| March | 70° | 56° | 3.3" | 0.0" | 9 | 0 | 57° – 70° |
| April | 76° | 63° | 3.6" | 0.0" | 8 | 0 | 65° – 73° |
| May | 82° | 70° | 4.6" | 0.0" | 7 | 0 | 73° – 79° |
| June | 88° | 76° | 5.5" | 0.0" | 10 | 0 | 79° – 84° |
| July | 90° | 78° | 4.4" | 0.0" | 10 | 0 | 81° – 86° |
| August | 90° | 78° | 5.4" | 0.0" | 10 | 0 | 80° – 88° |
| September | 87° | 74° | 6.2" | 0.0" | 11 | 0 | 78° – 85° |
| October | 80° | 65° | 5.2" | 0.0" | 8 | 0 | 69° – 77° |
| November | 71° | 56° | 4.2" | 0.0" | 8 | 0 | 58° – 69° |
| December | 64° | 49° | 4.4" | 0.2" | 11 | 0 | 50° – 61° |
| Year | 77° | 64° | 54.2" | 0.2" | 111 | 0 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 49° to 66°. June is the most reliable, staying within 5°.
Where San Leon’s 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 San Leon’s center.
- Snow: Houston Nwso, TX.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Houston Nwso, TX, 9 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 San Leon’s climate
What is the weather like in San Leon?
A typical July afternoon reaches 90°, a January night drops to 46°, and snow is almost unheard of. Milder January nights than 95% of U.S. towns; hotter July afternoons than 77% of U.S. towns.
How cold does it get in San Leon in winter?
January nights average 46°. About 9 nights a year reach 32° or below. In the coldest January of the last 30 years the month averaged 49°.
How much snow does San Leon get?
About 0.2 inches in a normal winter at Houston Nwso, TX, so most winters see none.
How hot does it get in San Leon?
July, with a typical high of 90° and a low of 78°. About 76 days a year reach 90° and 1 reach 100° (Houston Nwso, TX).
When is the first and last frost in San Leon?
In half of years the last spring frost (32°) comes by January 31 and the first fall frost by December 14, about 317 frost-free days, at Houston Nwso, TX.
What growing zone is San Leon in?
Zone 10a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 30°.
What is the best time of year to visit San Leon?
By one simple rule (highs of 62–84° and lows of 40° or more), January, February, March, April, May, October, November and December. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is San Leon getting warmer?
Yes: 1991–2020 averaged 1.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 54% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in San Leon.
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.