The desert Southwest is one of the most weather-dependent destinations in the US: get the season right and it’s glorious, get it wrong and it’s 106°F by lunchtime. Using NOAA’s 1991–2020 normals for Phoenix, Las Vegas and Albuquerque, here is when to go.
The answer first
The best time to visit the Southwest is spring (March–May) and autumn (October–November) — the shoulder seasons, when daytime highs are a comfortable 70s to 80s, rain is minimal and evenings are crisp. Avoid June–August, when Phoenix averages 104–106°F and Las Vegas tops 100°F. Winter is mild and excellent for hiking. These are NOAA 1991–2020 averages.
Southwest weather by season
| Season | Months | Phoenix avg high | Verdict |
|---|---|---|---|
| Winter | Dec–Feb | 57–71°F | Mild, great for hiking; cold nights |
| Spring | Mar–May | 78–94°F | Excellent early; hot by late May |
| Summer | Jun–Aug | 104–106°F | Avoid — extreme heat |
| Autumn | Sep–Nov | 76–100°F | Excellent Oct–Nov |
The sweet spots, city by city
The ideal months shift slightly between cities because of elevation — Albuquerque sits a mile high and runs cooler:
| City | Best spring window | Best autumn window |
|---|---|---|
| Phoenix, AZ | March (78°F) – early April | late October (89°F) – November |
| Las Vegas, NV | March (71°F) – April (79°F) | October (81°F) – November |
| Albuquerque, NM | April (70°F) – May (80°F) | September (83°F) – October (71°F) |
Albuquerque’s altitude makes it the most forgiving in summer and the coolest in winter; Phoenix is the hottest of the three year-round.
Why summer is the one to avoid
Southwest summer heat is “dry heat,” but at 104–106°F that distinction matters little after mid-morning. The upside: it’s genuinely dry. The downside: hiking and sightseeing are only safe at dawn. There’s also a monsoon — brief, sometimes intense afternoon storms in July and August — which is why Phoenix and Albuquerque actually get most of their meagre rain in late summer. See the monthly tables for the exact pattern.
Winter is underrated
Don’t overlook December–February. Phoenix averages a 68°F January high under near-constant sun, and the desert parks are quiet. The catch is cold nights — Phoenix lows near 46°F, colder in Albuquerque — so pack for a 30°F+ swing between afternoon and dawn. Understand that gap with how to read average high and low temperatures. The Southwest also dominates our driest cities ranking and features in best winter getaways.
Plan with the data
Run your exact dates through the packing & comfort tool, or open the Phoenix, Las Vegas and Albuquerque pages for the full 12-month breakdown. For a humid-warm alternative, compare with the best time to visit Florida.
All figures are NOAA 1991–2020 climate normals — 30-year averages, not forecasts. Check a live forecast and any heat advisories before you travel.