Weather in United States in August

August climate overview

Daytime highs across United States in August run from 27.5°C (New York) to 37.9°C (Las Vegas). In Las Vegas about 100% of August days reach 25°C. Nights average 24.1°C; the coldest 10% of nights in New York fall to 16°C or below.

Rainfall in August

Expect around 15 rainy days (1 mm or more) in August, with Las Vegas the driest (2 days) and Orlando the wettest (24 days). The wettest August at Las Vegas between 1991 and 2020 was 2007 with 65 mm; the driest was 2002 with 0 mm.

Sea temperature

The sea averages 27.4°C around United States in August - warmest at Florida (29.9°C). That is comfortable for swimming.

Sunshine and daylight

Around 6.4 hours of sunshine a day on average, out of 13.4 hours of daylight (sunshine estimated from cloud cover).

August against the rest of the year in United States

August is the 2nd warmest month of the twelve in United States. It is 0.3°C cooler than July and 1.8°C cooler in September. The hottest month here is July (31°C) and the coolest January (18°C).

Which part of United States in August?

• Most sunshine: Las Vegas, 10.7 h a day.
• Driest: Las Vegas, about 2 rainy days.
• Warmest sea: Florida, 30°C.
• Hottest: Las Vegas, 38°C by day - intense for sightseeing.
• Coolest (better for walking and cities): New York, 28°C.

What to pack for United States in August

Based on the averages: light, loose clothing and serious sun protection - midday highs sit around 31°C; a rain jacket - roughly 15 wet days; swimwear - the sea is 27°C.

Similar weather elsewhere in August

Within 1.5°C of United States's August daytime average: Agadir (32°C, sea 20°C), Sicily (32°C, sea 26°C), Madrid (32°C), Ayia Napa (32°C, sea 28°C), Albufeira (31°C, sea 21°C). See the full ranking for August.

Hawaii and New York offer more manageable warmth

Hawaii and New York are the better choices here if you want warm days without Las Vegas levels of heat. Both average 28°C during the day, but the evenings feel different: Hawaii stays at 24°C, while New York drops to 19°C. That makes New York more appealing if you like some relief after sunset; a light layer may be useful when sitting outside. Hawaii has the stronger balance for a warm-water holiday, with a 27°C sea and 7 rainy days. New York has 10 rainy days and a cooler sea at 23°C, so choose it for daytime warmth and fresher evenings rather than the warmest swimming conditions.

Las Vegas is dry, but the heat is the catch

Las Vegas is the hottest option in this selection, averaging 38°C by day. With just 2 rainy days, it suits travellers who prioritise dry weather, but that does not make it the easiest place for long periods outdoors. Plan active time towards the cooler parts of the day and leave room for indoor breaks around midday. Lightweight clothing, sun protection and ready access to water are sensible priorities. Nights average 26°C, so do not expect sunset to bring cool conditions. Choose Las Vegas if you are comfortable organising your holiday around heat; Hawaii or New York is a better fit if that sounds restrictive.

Florida is warm for swimming, with frequent rain

Florida works well if warm sea temperatures matter more to you than reliably dry days. The sea averages 30°C in both the Florida figures and Miami, making swimming appealing if cooler water puts you off. The trade-off is frequent rain: Florida has 23 rainy days, Miami 22 and Orlando 24. Keep outdoor plans flexible and carry a light waterproof rather than assuming every day will stay dry. Daytime averages sit at 31°C in Florida and Orlando, and 30°C in Miami. Nights remain warm across these destinations, so pack light evening clothing and prioritise comfortable sleeping conditions. This is a less suitable choice if rain would spoil your main holiday plans.