The best time to visit the USA
The best time to visit the USA for warm, sunny weather is June to September, when its destinations average a Sunshine Score of 72/100 with daytime highs around 29°C / 84°F. May and October are quieter shoulder-season alternatives with still-reliable sun. The sea is swimmable (21°C+) about 4 months a year, warmest in August at 25°C.
The USA by month, averaged across 194 destinations from long-term climate normals — the best stretch is highlighted.
| Month | Sunshine Score | Avg day high | Rain | Sea | For a trip |
|---|---|---|---|---|---|
| January | 21 | 7° / 45°F | 69 mm | 13° | Poor |
| February | 25 | 9° / 48°F | 68 mm | 13° | Mixed |
| March | 37 | 13° / 55°F | 77 mm | 15° | Mixed |
| April | 58 | 18° / 64°F | 80 mm | 17° | Very good |
| May | 71 | 23° / 73°F | 87 mm | 20° | Excellent |
| June | 71 | 28° / 82°F | 96 mm | 22° | Excellent |
| July | 70 | 30° / 86°F | 91 mm | 24° | Excellent |
| August | 71 | 30° / 86°F | 93 mm | 25° | Excellent |
| September | 74 | 26° / 79°F | 88 mm | 24° | Excellent |
| October | 65 | 20° / 68°F | 83 mm | 20° | Very good |
| November | 40 | 14° / 57°F | 71 mm | 18° | Good |
| December | 22 | 9° / 48°F | 84 mm | 14° | Poor |
When to go — and when to think twice
Best overall: June to September — the USA's warmest, most reliable stretch (Sunshine Score 72/100, ~29°C / 84°F days). Shoulder season: May and October — quieter, still sunny. Hottest: July, ~30°C / 86°F. Wettest: June (96 mm) — pack for showers.
Where to base yourself for sunshine: Boulder City (3,837 h/yr), Phoenix (3,833 h/yr), Ontario (3,804 h/yr). See where it's sunniest in the USA month by month, the hottest places in the USA, or every the USA destination with a full climate card.