Summer afternoons in Castalia are warmer than in 76% of U.S. towns
Midwinter brings lows of about 29°. By January nights alone, it runs milder than 72% of U.S. towns. December has warmed most since 1901–2000, part of a 1.2° rise. If you like long walks, April, May, September and October offer highs of 72–82°.
A year in Castalia at a glance
Each month’s typical high and low, and what it brings.
What stands out about Castalia’s climate
Compared with towns across the U.S., with Castalia’s place in North Carolina beside it.
What a year in Castalia feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 201 frost-free days a year
In half of years the last 32° night comes by April 11 and the first by October 29. Frost and day counts come from NOAA’s station at Louisburg, NC, 14 miles from the town’s center, at about the same height.
The 2023 USDA map puts Castalia’s center in zone 8a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 11°. 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 2 inches of snow a winter
Snow, measured at Louisburg, NC, falls mostly in January. Precipitation (rain plus melted snow) adds up to 47 inches a year; September is the wettest month and February the driest. Rain or snow falls on about 109 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Castalia
70% of the work is heating. Months averaging under 55° run from November through March.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Louisburg, NC.
Living with Castalia’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
201 frost-free days in zone 8a. The last frost comes by Apr 11 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 29.
Months with highs of 62–84° and lows of 40° or more: April, May, September and October.
Parks & trails →Of the yearly building losses FEMA expects in Castalia from natural hazards, hurricanes are the largest share (28%); heat waves, cold waves, winter storms and ice storms together are 13%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Castalia and similar climates
TownRatings has no climate map of the towns around Castalia yet.
Climates most like Castalia’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 |
|---|---|---|---|---|
| Castalia, NC | 29° | 90° | 47" | 1.7" |
| Gaffney, SC | 30° | 90° | 47" | 1.9" |
| Walnut Ridge, AR | 28° | 90° | 49" | 0.9" |
| Sikeston, MO | 28° | 90° | 49" | 3.1" |
| Newport, TN | 28° | 88° | 47" | 3.3" |
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 Castalia averaged 1.2° warmer than the 1900s. The biggest change is in December (+2.7°).
A smaller shift than in 62% 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 Castalia compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Castalia’s place among North Carolina’s.
Castalia weather by month
Highs, lows and precipitation from NOAA’s grid at Castalia’s center; snow, wet days and snow on the ground from Louisburg, NC. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 51° | 29° | 3.5" | 0.9" | 10 | 2 | 35° – 46° |
| February | 55° | 32° | 2.9" | 0.4" | 9 | 1 | 34° – 51° |
| March | 62° | 37° | 4.2" | 0.2" | 10 | 0 | 43° – 57° |
| April | 72° | 46° | 3.6" | 0.0" | 9 | 0 | 54° – 65° |
| May | 79° | 55° | 3.5" | 0.0" | 10 | 0 | 62° – 73° |
| June | 86° | 64° | 4.5" | 0.0" | 10 | 0 | 71° – 80° |
| July | 90° | 68° | 5.0" | 0.0" | 10 | 0 | 75° – 82° |
| August | 88° | 67° | 4.6" | 0.0" | 9 | 0 | 73° – 81° |
| September | 82° | 60° | 5.0" | 0.0" | 8 | 0 | 68° – 77° |
| October | 72° | 48° | 3.4" | 0.0" | 7 | 0 | 56° – 66° |
| November | 62° | 38° | 3.2" | 0.0" | 8 | 0 | 45° – 56° |
| December | 54° | 32° | 3.4" | 0.2" | 10 | 0 | 34° – 55° |
| Year | 71° | 48° | 46.7" | 1.7" | 109 | 3 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 34° to 55°. July is the most reliable, staying within 7°.
Where Castalia’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 Castalia’s center.
- Snow: Louisburg, NC.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Louisburg, NC, 14 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 Castalia’s climate
What is the weather like in Castalia?
A typical July afternoon reaches 90°, a January night drops to 29°, and about 2 inches of snow falls in a normal winter. Milder January nights than 72% of U.S. towns; hotter July afternoons than 76% of U.S. towns.
How cold does it get in Castalia in winter?
January nights average 29°. About 98 nights a year reach 32° or below. In the coldest January of the last 30 years the month averaged 35°.
How much snow does Castalia get?
About 1.7 inches in a normal winter at Louisburg, NC, most of it in January, with snow on the ground about 3 days a year.
How hot does it get in Castalia?
July, with a typical high of 90° and a low of 68°. About 51 days a year reach 90° and 1 reach 100° (Louisburg, NC).
When is the first and last frost in Castalia?
In half of years the last spring frost (32°) comes by April 11 and the first fall frost by October 29, about 201 frost-free days, at Louisburg, NC.
What growing zone is Castalia in?
Zone 8a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 11°.
What is the best time of year to visit Castalia?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Castalia getting warmer?
Yes: 1991–2020 averaged 1.2° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 62% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Castalia.
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.