Country guide
United States weather by month
Spring and autumn are the clearest starting points for a United States city holiday, while summer into early autumn offers warmer seas for beach trips. Average daytime temperatures rise from 18°C in January to 31°C in July and August, then ease to 26°C in October. The catch is that the warmer months also bring more rainy days. Location matters just as much as timing: Miami and New York sit at very different ends of the temperature range.
- Hottest month
- 31.2°CJuly
- Coolest month
- 17.9°CJanuary
- Warmest sea
- 27.4°CAugust
- Destinations tracked
- 6warmest: Miami
United States, month by month
A little perspective
United States through the year
Country figures are the mean of the 6 destinations listed below; individual resorts can differ by several degrees.
| Month | Day | Night | Sea | Sun/day | Rain mm | Rainy days | Days 25°C+ |
|---|---|---|---|---|---|---|---|
| January | 17.9°C | 10.7°C | 19.3°C | 5.3 | 51 | 7 | 19% |
| February | 19.0°C | 11.4°C | 18.8°C | 5.8 | 47 | 7 | 23% |
| March | 21.4°C | 13.4°C | 19.3°C | 6.2 | 58 | 7 | 37% |
| Aprilbest | 24.4°C | 16.2°C | 20.8°C | 6.9 | 49 | 7 | 60% |
| Maybest | 27.4°C | 19.3°C | 22.9°C | 7.5 | 63 | 9 | 81% |
| June | 29.8°C | 22.5°C | 25.3°C | 6.8 | 101 | 13 | 92% |
| July | 31.2°C | 24.2°C | 26.9°C | 6.7 | 91 | 14 | 98% |
| August | 30.9°C | 24.1°C | 27.4°C | 6.4 | 103 | 15 | 96% |
| September | 29.0°C | 22.4°C | 26.7°C | 6.1 | 97 | 13 | 89% |
| Octoberbest | 25.7°C | 19.0°C | 25.0°C | 6.1 | 71 | 9 | 74% |
| November | 21.9°C | 15.1°C | 22.7°C | 5.6 | 46 | 7 | 47% |
| December | 18.8°C | 12.2°C | 20.8°C | 5.1 | 52 | 7 | 29% |
Day = average daytime high, night = average night-time low, 1991-2020.Sun is hours per day; rainy days count 1 mm or more.
Day, night and sea
Monthly average temperatures, 1991-2020
- Day
- Night
- Sea
When to go to United States
Daytime highs average 25°C or more in May, June, July, August, September, October. The sea reaches a swimmable 22°C from May to November. Winter (December to February) averages 19°C by day - mild rather than warm. August is the wettest month (103 mm) and November the driest (46 mm).
Destinations in United States
Each has a 12-month table; our most searched places have month-by-month detail pages.
| Destination | Hottest month | Coolest month | Months 25°C+ | Sea (warmest) | Flight from London |
|---|---|---|---|---|---|
| Florida | July 31°C | January 22°C | 8 | 30°C | 9 h 30 min |
| New York | July 29°C | January 3°C | 3 | 23°C | 7 h 42 min |
| Las Vegas | July 39°C | December 13°C | 7 | - | 11 h 18 min |
| Orlandoin Florida | July 31°C | January 21°C | 7 | - | 9 h 30 min |
| Miamiin Florida | July 30°C | January 23°C | 9 | 30°C | 9 h 42 min |
| Hawaii | September 28°C | February 24°C | 9 | 27°C | 15 h 18 min |
Warmest place in United States each month
| Month | Warmest destination | Day | Coolest destination | Day | Warmest sea |
|---|---|---|---|---|---|
| January | Hawaii | 25°C | New York | 3°C | Hawaii 25°C |
| February | Hawaii | 24°C | New York | 5°C | Hawaii 24°C |
| March | Miami | 25°C | New York | 9°C | Miami 24°C |
| April | Orlando | 27°C | New York | 15°C | Florida 25°C |
| May | Las Vegas | 30°C | New York | 21°C | Florida 27°C |
| June | Las Vegas | 36°C | New York | 26°C | Florida 29°C |
| July | Las Vegas | 39°C | Hawaii | 28°C | Florida 30°C |
| August | Las Vegas | 38°C | New York | 28°C | Florida 30°C |
| September | Las Vegas | 34°C | New York | 24°C | Florida 29°C |
| October | Miami | 28°C | New York | 17°C | Miami 28°C |
| November | Hawaii | 26°C | New York | 11°C | Miami 26°C |
| December | Hawaii | 25°C | New York | 6°C | Hawaii 25°C |
How the weather changes through the year
Winter is the cooler end of the year, so do not treat a mild daytime average as a promise of warm evenings. January and February nights average 11°C, making layers useful. Spring brings a steady rise in warmth: April reaches 24°C by day with 7 rainy days, a practical balance for time outdoors. By June, daytime temperatures reach 30°C and rain becomes more frequent. July and August are the hottest months, with nights staying warm too. Autumn then eases the heat rather than switching straight to cold weather. November averages 22°C by day and has 6 rainy days, making it worth considering if swimming is not your priority.
Choose the destination before choosing your clothes
The national average is a broad guide, not a packing forecast for every part of the United States. Miami is the warmest destination year-round, with an average daytime temperature of 27°C; New York is the coolest at 16°C. That makes Miami the stronger starting point if warmth drives your choice, but neither annual figure tells you what every month will feel like. Florida, Orlando, Las Vegas and Hawaii also feature in the holiday choices here, and the overall monthly curve should not be read as an identical forecast for each. Choose your destination first, then use its monthly temperatures to decide how much warm clothing to bring.
When to go for beaches or city days
For a beach-led trip, sea temperature is more useful than daytime warmth alone. The average sea reaches 27°C from July through September, but this overlaps with frequent rainy days: August has 15. October offers a different balance, with sea temperatures of 25°C and 9 rainy days, alongside less intense daytime heat. For cities, April and October are sensible starting points if you prefer walking without the highest summer temperatures. Plan a less demanding midday schedule in the hottest months and keep outdoor plans flexible. Spring suits travellers who value milder air over warmer water; early autumn makes more sense when swimming is central to the trip.
A little more detail
United States weather FAQs
Plain answers, grounded in the averages.
When is the best time to visit United States?
Weighing warmth, low rainfall and sunshine across 6 destinations, the best months for United States are May, April, October. July is the hottest month (average high 31.2°C) and January the coolest (17.9°C).
How many months is United States over 25°C?
6 months average a daytime high of 25°C or more across our United States destinations.
Which is the hottest place in United States?
Over the year, Miami has the highest average daytime temperature of the 6 United States destinations we track (27.0°C averaged across all months).
Which destination is warmest overall?
Miami is the warmest year-round, averaging 27°C by day. New York is the coolest at 16°C. These are annual averages rather than temperatures to expect on every visit, so the month still matters when choosing between them.
Which month has the fewest rainy days?
November has the lowest country-average figure, at 6 rainy days. Its average daytime temperature is 22°C, so it offers a useful balance for travellers prioritising outdoor city time over peak warmth. It is not a guarantee of dry weather throughout your stay.
Is winter a good choice for swimming?
Winter is less convincing if warm water is essential. Average sea temperatures are 21°C in December and 19°C in January and February, compared with 27°C from July through September. Your destination and tolerance for cooler water should guide the decision.
About these averages
ERA5-Land climate reanalysis via Open-Meteo (11 km grid), 1991-2020
Averages computed from daily values at 6 destination points.Records are the highest and lowest daily values in that 30-year period, not all-time records. These are climate averages, not a forecast for your trip. How we measure holiday weather
- Hot · 25°C+
- Warm · 20°C to below 25°C
- Mild · 15°C to below 20°C
- Cool · below 15°C