Nelson reaches 100° on about 104 days a year, more than all but 62 U.S. towns
A typical July afternoon reaches 104°, a January night drops to 39°, and snow is almost unheard of.
A year in Nelson at a glance
Each month’s typical high and low, and what it brings.
What stands out about Nelson’s climate
Compared with towns across the U.S., with Nelson’s place in Arizona beside it.
What a year in Nelson feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 308 frost-free days a year
In half of years the last 32° night comes by February 6 and the first by December 9. Frost and day counts come from NOAA’s station at Picacho 8 Se, AZ, 17 miles from the town’s center, at about the same height.
The 2023 USDA map puts Nelson’s center in zone 9a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 25°. 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 10 inches of rain a year
August is the wettest month and June the driest. Rain falls on about 45 days a year. Snow is rare: about 0.0" in a normal year at Tucson 17 Nw, AZ, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Nelson
24% 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 Picacho 8 Se, AZ.
Living with Nelson’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
308 frost-free days in zone 9a. The last frost comes by Feb 6 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 9.
Months with highs of 62–84° and lows of 40° or more: February, March and November.
Parks & trails →Of the yearly building losses FEMA expects in Nelson from natural hazards, river flooding is the largest share (63%); heat waves, cold waves, winter storms and ice storms together are 26%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Nelson and its neighbors
Every town next door is within a degree of Nelson in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Nelson’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 |
|---|---|---|---|---|
| Nelson, AZ | 39° | 104° | 10" | 0.0" |
| Enterprise, NV | 37° | 103° | 5" | 0.2" |
| Desert Hot Springs, CA | 42° | 105° | 7" | 0.8" |
| St. George, UT | 33° | 103° | 8" | 1.2" |
| Eagle Pass, TX | 41° | 98° | 19" | 0.0" |
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 Nelson averaged 1.5° warmer than the 1900s. The biggest change is in March (+2.5°).
A bigger shift than in 60% 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 Nelson compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Nelson’s place among Arizona’s.
Nelson weather by month
Highs, lows and precipitation from NOAA’s grid at Nelson’s center; snow, wet days and snow on the ground from Tucson 17 Nw, AZ. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 68° | 39° | 0.8" | 0.0" | 4 | 0 | 49° – 59° |
| February | 71° | 41° | 1.1" | 0.0" | 4 | 0 | 51° – 62° |
| March | 77° | 46° | 0.7" | 0.0" | 3 | 0 | 55° – 68° |
| April | 85° | 52° | 0.3" | 0.0" | 1 | 0 | 62° – 74° |
| May | 94° | 60° | 0.2" | 0.0" | 1 | 0 | 72° – 81° |
| June | 104° | 70° | 0.2" | 0.0" | 1 | 0 | 82° – 90° |
| July | 104° | 76° | 1.3" | 0.0" | 8 | 0 | 87° – 92° |
| August | 102° | 75° | 2.0" | 0.0" | 8 | 0 | 85° – 93° |
| September | 98° | 69° | 1.0" | 0.0" | 5 | 0 | 79° – 86° |
| October | 88° | 57° | 0.6" | 0.0" | 3 | 0 | 69° – 78° |
| November | 77° | 46° | 0.7" | 0.0" | 2 | 0 | 52° – 68° |
| December | 66° | 38° | 1.1" | 0.0" | 4 | 0 | 48° – 57° |
| Year | 86° | 56° | 9.9" | 0.0" | 45 | 0 |
How much a month can swing
A normal is an average. November swings the most: from 1991 to 2020 its average ranged from 52° to 68°. July is the most reliable, staying within 5°.
Where Nelson’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 Nelson’s center.
- Snow: Tucson 17 Nw, AZ.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Picacho 8 Se, AZ, 17 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 Nelson’s climate
What is the weather like in Nelson?
A typical July afternoon reaches 104°, a January night drops to 39°, and snow is almost unheard of. Milder January nights than 87% of U.S. towns; hotter July afternoons than all but 84 U.S. towns.
How cold does it get in Nelson in winter?
December nights average 38°. About 10 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 48°.
How much snow does Nelson get?
About 0.0 inches in a normal winter at Tucson 17 Nw, AZ, so most winters see none.
How hot does it get in Nelson?
July, with a typical high of 104° and a low of 76°. About 176 days a year reach 90° and 104 reach 100° (Picacho 8 Se, AZ).
When is the first and last frost in Nelson?
In half of years the last spring frost (32°) comes by February 6 and the first fall frost by December 9, about 308 frost-free days, at Picacho 8 Se, AZ.
What growing zone is Nelson in?
Zone 9a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 25°.
What is the best time of year to visit Nelson?
By one simple rule (highs of 62–84° and lows of 40° or more), February, March and November. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Nelson getting warmer?
Yes: 1991–2020 averaged 1.5° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 60% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Nelson.
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.