Photo: Renelibrary · CC BY-SA 4.0Castroville reaches 100° on about 15 days a year, more than 93% of U.S. towns
A typical July afternoon reaches 96°, a January night drops to 40°, and snow is almost unheard of.
A year in Castroville at a glance
Each month’s typical high and low, and what it brings.
What stands out about Castroville’s climate
Compared with towns across the U.S., with Castroville’s place in Texas beside it.
What a year in Castroville feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 283 frost-free days a year
In half of years the last 32° night comes by February 24 and the first by December 2. Frost and day counts come from NOAA’s station at Lytle 3w, TX, 9 miles from the town’s center, at about the same height.
The 2023 USDA map puts Castroville’s center in zone 9a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 23°. 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 29 inches of rain a year
May is the wettest month and February the driest. Rain falls on about 47 days a year. Snow is rare: about 0.0" in a normal year at Riomedina, TX, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Castroville
27% of the work is heating, so air conditioning is the bigger bill. Months averaging under 55°: December and 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 Lytle 3w, TX.
Living with Castroville’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
283 frost-free days in zone 9a. The last frost comes by Feb 24 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 2.
Months with highs of 62–84° and lows of 40° or more: January, February, March, April, October, November and December. 1.6 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Castroville from natural hazards, river flooding is the largest share (66%); heat waves, cold waves, winter storms and ice storms together are 7%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Castroville and similar climates
TownRatings has no climate map of the towns around Castroville yet.
Climates most like Castroville’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 |
|---|---|---|---|---|
| Castroville, TX | 40° | 96° | 29" | 0.0" |
| Chico, CA | 38° | 96° | 31" | 0.0" |
| Lawton, OK | 29° | 96° | 32" | 1.8" |
| Grants Pass, OR | 34° | 90° | 33" | 0.9" |
| Corona de Tucson, AZ | 36° | 96° | 14" | 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 Castroville averaged 1.0° warmer than the 1900s. The biggest change is in February (+2.0°).
A smaller shift than in 75% 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 Castroville compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Castroville’s place among Texas’.
Castroville weather by month
Highs, lows and precipitation from NOAA’s grid at Castroville’s center; snow, wet days and snow on the ground from Riomedina, TX. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 65° | 40° | 1.7" | 0.0" | 4 | 0 | 48° – 58° |
| February | 69° | 45° | 1.6" | 0.0" | 4 | 0 | 49° – 65° |
| March | 76° | 51° | 2.3" | 0.0" | 5 | 0 | 57° – 69° |
| April | 82° | 58° | 2.4" | 0.0" | 3 | 0 | 64° – 76° |
| May | 88° | 66° | 3.7" | 0.0" | 5 | 0 | 73° – 81° |
| June | 93° | 72° | 3.0" | 0.0" | 4 | 0 | 79° – 87° |
| July | 96° | 73° | 2.3" | 0.0" | 4 | 0 | 80° – 88° |
| August | 97° | 73° | 2.3" | 0.0" | 4 | 0 | 81° – 89° |
| September | 91° | 68° | 3.4" | 0.0" | 4 | 0 | 76° – 85° |
| October | 83° | 59° | 3.1" | 0.0" | 4 | 0 | 68° – 76° |
| November | 73° | 49° | 2.0" | 0.0" | 3 | 0 | 56° – 66° |
| December | 66° | 42° | 1.7" | 0.0" | 4 | 0 | 47° – 57° |
| Year | 82° | 58° | 29.4" | 0.0" | 47 | 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 65°. October is the most reliable, staying within 7°.
Where Castroville’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 Castroville’s center.
- Snow: Riomedina, TX.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Lytle 3w, 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 Castroville’s climate
What is the weather like in Castroville?
A typical July afternoon reaches 96°, a January night drops to 40°, and snow is almost unheard of. Milder January nights than 89% of U.S. towns; hotter July afternoons than 97% of U.S. towns.
How cold does it get in Castroville in winter?
January nights average 40°. About 17 nights a year reach 32° or below. In the coldest January of the last 30 years the month averaged 48°.
How much snow does Castroville get?
About 0.0 inches in a normal winter at Riomedina, TX, so most winters see none.
How hot does it get in Castroville?
July, with a typical high of 96° and a low of 73°. About 120 days a year reach 90° and 15 reach 100° (Lytle 3w, TX).
When is the first and last frost in Castroville?
In half of years the last spring frost (32°) comes by February 24 and the first fall frost by December 2, about 283 frost-free days, at Lytle 3w, TX.
What growing zone is Castroville in?
Zone 9a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 23°.
What is the best time of year to visit Castroville?
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 Castroville getting warmer?
Yes: 1991–2020 averaged 1.0° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 75% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Castroville.
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.