Photo: W.marsh · CC BY-SA 3.0New Castle gets more rain and snow than 85% of U.S. towns: 50 inches of precipitation a year
High summer brings afternoon highs near 86°. From frosty January to warm July, readings climb 63°. The frost-free window for a garden runs roughly April 12 to October 25.
A year in New Castle at a glance
Each month’s typical high and low, and what it brings.
What stands out about New Castle’s climate
Compared with towns across the U.S., with New Castle’s place in Kentucky beside it.
What a year in New Castle feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 193 frost-free days a year
In half of years the last 32° night comes by April 12 and the first by October 25. Frost and day counts come from NOAA’s station at Crestwood 4ne, KY, 14 miles from the town’s center, at about the same height.
The 2023 USDA map puts New Castle’s center in zone 6b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −2°. 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 12 inches of snow a winter
Snow, measured at Madison Sewage Plt, IN, falls mostly in January. Precipitation (rain plus melted snow) adds up to 50 inches a year; May is the wettest month and September the driest. Rain or snow falls on about 115 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in New Castle
79% 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 Crestwood 4ne, KY.
Living with New Castle’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
193 frost-free days in zone 6b. The last frost comes by Apr 12 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 25.
Months with highs of 62–84° and lows of 40° or more: April, May, June, September and October.
Parks & trails →Of the yearly building losses FEMA expects in New Castle from natural hazards, river flooding is the largest share (60%); heat waves, cold waves, winter storms and ice storms together are 6%. Normals are averages; the hazards page covers the extremes.
Natural hazards →New Castle and similar climates
TownRatings has no climate map of the towns around New Castle yet.
Climates most like New Castle’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 |
|---|---|---|---|---|
| New Castle, KY | 24° | 86° | 50" | 12" |
| Lansdale, PA | 22° | 86° | 49" | 13" |
| Hockessin, DE | 24° | 86° | 48" | 12" |
| Forest, VA | 26° | 87° | 47" | 12" |
| Ocean Acres, NJ | 25° | 85° | 47" | 10" |
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 New Castle averaged 1.2° warmer than the 1900s. The biggest change is in December (+2.4°).
A smaller shift than in 65% 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 New Castle compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with New Castle’s place among Kentucky’s.
New Castle weather by month
Highs, lows and precipitation from NOAA’s grid at New Castle’s center; snow, wet days and snow on the ground from Madison Sewage Plt, IN. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 41° | 24° | 3.6" | 4.4" | 9 | 25° – 42° |
| February | 46° | 26° | 3.5" | 3.6" | 8 | 24° – 45° |
| March | 55° | 34° | 4.5" | 1.0" | 10 | 38° – 57° |
| April | 67° | 43° | 4.9" | 0.1" | 11 | 49° – 62° |
| May | 76° | 53° | 5.5" | 0.0" | 13 | 58° – 72° |
| June | 83° | 61° | 5.0" | 0.0" | 11 | 68° – 76° |
| July | 86° | 65° | 4.9" | 0.0" | 10 | 70° – 80° |
| August | 85° | 64° | 3.6" | 0.0" | 8 | 70° – 80° |
| September | 80° | 56° | 3.4" | 0.0" | 7 | 64° – 75° |
| October | 68° | 45° | 3.6" | 0.2" | 8 | 52° – 63° |
| November | 55° | 35° | 3.5" | 0.0" | 9 | 39° – 50° |
| December | 45° | 28° | 4.2" | 3.0" | 10 | 25° – 47° |
| Year | 65° | 44° | 50.4" | 12.3" | 115 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 25° to 47°. June is the most reliable, staying within 8°.
Where New Castle’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 New Castle’s center.
- Snow: Madison Sewage Plt, IN.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Crestwood 4ne, KY, 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 New Castle’s climate
What is the weather like in New Castle?
A typical July afternoon reaches 86°, a January night drops to 24°, and about 12 inches of snow falls in a normal winter. Milder January nights than 59% of U.S. towns; hotter July afternoons than 57% of U.S. towns.
How cold does it get in New Castle in winter?
January nights average 24°. About 105 nights a year reach 32° or below and 2 reach 0° or below. In the coldest January of the last 30 years the month averaged 25°.
How much snow does New Castle get?
About 12 inches in a normal winter at Madison Sewage Plt, IN, most of it in January.
How hot does it get in New Castle?
July, with a typical high of 86° and a low of 65°. About 37 days a year reach 90° (Crestwood 4ne, KY).
When is the first and last frost in New Castle?
In half of years the last spring frost (32°) comes by April 12 and the first fall frost by October 25, about 193 frost-free days, at Crestwood 4ne, KY.
What growing zone is New Castle in?
Zone 6b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −2°.
What is the best time of year to visit New Castle?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, June, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is New Castle getting warmer?
Yes: 1991–2020 averaged 1.2° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 65% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in New Castle.
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.