Photo: The original uploader was Danman083 at English Wikipedia. · CC BY-SA 3.0Oro Valley reaches 100° on about 68 days a year, more than all but 107 U.S. towns
A typical July afternoon reaches 100°, a January night drops to 38°, and snow is almost unheard of.
A year in Oro Valley at a glance
Each month’s typical high and low, and what it brings.
What stands out about Oro Valley’s climate
Compared with towns across the U.S., with Oro Valley’s place in Arizona beside it.
What a year in Oro Valley feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 222 frost-free days a year
In half of years the last 32° night comes by April 2 and the first by November 11. Frost and day counts come from NOAA’s station at Catalina Sp, AZ, 2.7 miles from the town’s center, at about the same height.
The 2023 USDA map puts Oro Valley’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 13 inches of rain a year
August is the wettest month and May the driest. Rain falls on about 40 days a year. Snow is rare: about 0.0" in a normal year at Tucson Camp Ave Exp, AZ, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Oro Valley
47% of the work is heating, so air conditioning is the bigger bill. Months averaging under 55° run from December through February.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Catalina Sp, AZ.
Living with Oro Valley’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
222 frost-free days in zone 9a. The last frost comes by Apr 2 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Nov 11.
Months with highs of 62–84° and lows of 40° or more: February, March, April and November. 78 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Oro Valley from natural hazards, river flooding is the largest share (63%); heat waves, cold waves, winter storms and ice storms together are 25%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Oro Valley and its neighbors
Catalina has the coldest January nights next door (35°, 3° colder) and Casas Adobes the hottest July afternoons (101°, 2° warmer). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Oro Valley’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 |
|---|---|---|---|---|
| Oro Valley, AZ | 38° | 100° | 13" | 0.0" |
| Orange Cove, CA | 39° | 98° | 12" | 0.0" |
| Eagle Pass, TX | 41° | 98° | 19" | 0.0" |
| Ivins, UT | 32° | 100° | 11" | 1.2" |
| Summerlin South, NV | 35° | 102° | 5" | 0.2" |
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 Oro Valley averaged 1.4° warmer than the 1900s. The biggest change is in March (+2.4°).
A bigger shift than in 53% 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 Oro Valley compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Oro Valley’s place among Arizona’s.
Oro Valley weather by month
Highs, lows and precipitation from NOAA’s grid at Oro Valley’s center; snow, wet days and snow on the ground from Tucson Camp Ave Exp, AZ. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 65° | 38° | 1.2" | 0.0" | 4 | 0 | 47° – 57° |
| February | 68° | 40° | 1.2" | 0.0" | 4 | 0 | 48° – 59° |
| March | 74° | 45° | 0.9" | 0.0" | 3 | 0 | 53° – 65° |
| April | 81° | 50° | 0.3" | 0.0" | 1 | 0 | 59° – 71° |
| May | 90° | 58° | 0.2" | 0.0" | 1 | 0 | 69° – 79° |
| June | 100° | 68° | 0.2" | 0.0" | 1 | 0 | 79° – 87° |
| July | 100° | 73° | 2.0" | 0.0" | 6 | 0 | 83° – 89° |
| August | 98° | 72° | 2.3" | 0.0" | 8 | 0 | 83° – 90° |
| September | 94° | 67° | 1.4" | 0.0" | 4 | 0 | 76° – 83° |
| October | 85° | 56° | 0.6" | 0.0" | 3 | 0 | 67° – 75° |
| November | 74° | 45° | 0.8" | 0.0" | 2 | 0 | 51° – 66° |
| December | 64° | 38° | 1.4" | 0.0" | 4 | 0 | 46° – 55° |
| Year | 83° | 54° | 12.6" | 0.0" | 40 | 0 |
How much a month can swing
A normal is an average. November swings the most: from 1991 to 2020 its average ranged from 51° to 66°. July is the most reliable, staying within 5°.
Where Oro Valley’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 Oro Valley’s center.
- Snow: Tucson Camp Ave Exp, AZ.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Catalina Sp, AZ, 2.7 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 Oro Valley’s climate
What is the weather like in Oro Valley?
A typical July afternoon reaches 100°, a January night drops to 38°, and snow is almost unheard of. Milder January nights than 85% of U.S. towns; hotter July afternoons than all but 136 U.S. towns.
How cold does it get in Oro Valley in winter?
December nights average 38°. About 67 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 46°.
How much snow does Oro Valley get?
About 0.0 inches in a normal winter at Tucson Camp Ave Exp, AZ, so most winters see none.
How hot does it get in Oro Valley?
July, with a typical high of 100° and a low of 73°. About 157 days a year reach 90° and 68 reach 100° (Catalina Sp, AZ).
When is the first and last frost in Oro Valley?
In half of years the last spring frost (32°) comes by April 2 and the first fall frost by November 11, about 222 frost-free days, at Catalina Sp, AZ.
What growing zone is Oro Valley 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 Oro Valley?
By one simple rule (highs of 62–84° and lows of 40° or more), February, March, April and November. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Oro Valley getting warmer?
Yes: 1991–2020 averaged 1.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 53% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Oro Valley.
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.