Last updated: March 2, 2024
The weather in Heathrow, United States, during May is characterized by an average temperature of 25°C (77°F). Highs can soar to 34°C (93°F), while lows may dip to 15°C (59°F). Typically, the humidity level in Heathrow throughout May hovers around 68%.
Minimum temperature
Average temperature
Maximum temperature
Humidity
In May, Heathrow averages 107 mm (4.2 inches) of rainfall, typically over the course of 11 rainy days. The month enjoys an average of 13 hours 35 minutes of daylight, with the sun shining for approximately 10 hours 28 minutes each day. Additionally, there is a 49% probability of sunny days during this period.
Precipitation
Rainy days
Sunshine hours
Chance of sun
In May, the UV Index in Heathrow reaches a maximum of 11, indicating a level of Extreme exposure. The most intense UV radiation typically occurs between 13:00 and 15:00, during which unprotected skin may burn in as little as 10 minutes.
| 07:00 | 08:00 | 09:00 | 10:00 | 11:00 | 12:00 | 13:00 | 14:00 | 15:00 | 16:00 | 17:00 | 18:00 | 19:00 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UVI | 1 | 1 | 3 | 5 | 8 | 10 | 11 | 11 | 9 | 6 | 4 | 2 | 1 |
| Exposure | Low | Moderate | VeryHigh | Extreme | VeryHigh | High | Moderate | Low | |||||
| Time to burn | 45 min | 30 min | 15 min | 10 min | 15 min | 25 min | 30 min | 45 min | |||||