Photo: Acroterion · CC BY-SA 4.0Less rain and snow falls on Newcastle than on 92% of U.S. towns: 17 inches a year
In July the day’s top temperature is typically 86°. Precipitation peaks in May and eases off in January. By January nights alone, it runs colder than 91% of U.S. towns. Picnics, hikes and garden evenings suit May, June and September, with highs of 65–77°.
A year in Newcastle at a glance
Each month’s typical high and low, and what it brings.
What stands out about Newcastle’s climate
Compared with towns across the U.S., with Newcastle’s place in Wyoming beside it.
What a year in Newcastle feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 143 frost-free days a year
In half of years the last 32° night comes by May 13 and the first by October 3. Frost and day counts come from NOAA’s station at Newcastle, WY, 0.4 miles from the town’s center, at about the same height.
The 2023 USDA map puts Newcastle’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −18°. 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 39 inches of snow a winter
Snow, measured at Newcastle, WY, falls mostly in February. Precipitation (rain plus melted snow) adds up to 17 inches a year; May is the wettest month and January the driest. Rain or snow falls on about 88 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Newcastle
91% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through May.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Newcastle, WY.
Living with Newcastle’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
143 frost-free days in zone 5a. The last frost comes by May 13 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 3.
Months with highs of 62–84° and lows of 40° or more: May, June and September. 1.4 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Newcastle from natural hazards, river flooding is the largest share (28%); heat waves, cold waves, winter storms and ice storms together are 28%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Newcastle and similar climates
TownRatings has no climate map of the towns around Newcastle yet.
Climates most like Newcastle’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 |
|---|---|---|---|---|
| Newcastle, WY | 12° | 86° | 17" | 39" |
| Gypsum, CO | 11° | 86° | 14" | 39" |
| Lockwood, MT | 15° | 88° | 15" | 35" |
| Pierre, SD | 9° | 88° | 19" | 37" |
| Taos, NM | 11° | 84° | 13" | 28" |
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 Newcastle averaged 1.3° warmer than the 1900s. The biggest change is in March (+3.5°).
A smaller shift than in 56% 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 Newcastle compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Newcastle’s place among Wyoming’s.
Newcastle weather by month
Highs, lows and precipitation from NOAA’s grid at Newcastle’s center; snow, wet days and snow on the ground from Newcastle, WY. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 35° | 12° | 0.5" | 6.8" | 6 | 17 | 16° – 33° |
| February | 38° | 14° | 0.6" | 7.7" | 6 | 13 | 13° – 35° |
| March | 48° | 23° | 0.8" | 4.9" | 6 | 7 | 25° – 46° |
| April | 56° | 30° | 1.7" | 5.0" | 8 | 2 | 37° – 50° |
| May | 65° | 40° | 2.9" | 0.6" | 11 | 0 | 47° – 59° |
| June | 77° | 50° | 2.7" | 0.0" | 11 | 0 | 56° – 70° |
| July | 86° | 57° | 2.4" | 0.0" | 9 | 0 | 63° – 77° |
| August | 85° | 54° | 1.7" | 0.0" | 7 | 0 | 64° – 75° |
| September | 74° | 45° | 1.2" | 0.2" | 6 | 0 | 53° – 65° |
| October | 59° | 32° | 1.3" | 1.4" | 7 | 1 | 36° – 51° |
| November | 45° | 21° | 0.6" | 5.5" | 5 | 7 | 23° – 43° |
| December | 35° | 12° | 0.6" | 6.8" | 6 | 12 | 15° – 30° |
| Year | 59° | 32° | 16.9" | 38.9" | 88 | 59 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 13° to 35°. August is the most reliable, staying within 11°.
Where Newcastle’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 Newcastle’s center.
- Snow: Newcastle, WY (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Newcastle, WY, 0.4 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 Newcastle’s climate
What is the weather like in Newcastle?
A typical July afternoon reaches 86°, a January night drops to 12°, and about 39 inches of snow falls in a normal winter. Colder January nights than 91% of U.S. towns; hotter July afternoons than 55% of U.S. towns.
How cold does it get in Newcastle in winter?
January nights average 12°. About 168 nights a year reach 32° or below and 14 reach 0° or below. In the coldest January of the last 30 years the month averaged 16°.
How much snow does Newcastle get?
About 39 inches in a normal winter at Newcastle, WY, most of it in February, with snow on the ground about 59 days a year.
How hot does it get in Newcastle?
July, with a typical high of 86° and a low of 57°. About 34 days a year reach 90° and 3 reach 100° (Newcastle, WY).
When is the first and last frost in Newcastle?
In half of years the last spring frost (32°) comes by May 13 and the first fall frost by October 3, about 143 frost-free days, at Newcastle, WY.
What growing zone is Newcastle in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −18°.
What is the best time of year to visit Newcastle?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Newcastle getting warmer?
Yes: 1991–2020 averaged 1.3° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 56% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Newcastle.
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.