May weather forecastHeraklion, Greece

May
Weather in May
May brings a pronounced increase in both daylight hours and heat, demonstrating a true spring atmosphere. Sunshine duration extends to 9.7 hours, and combined with a sea temperature of 19.5°C (67.1°F), it makes for an ideal climate for outdoor activities. Compared to April, rainfall reduces drastically, making cloudy days an anomaly. As Heraklion shifts closer to its peak summer conditions, anticipate a significant rise in temperatures by June. Despite these changes, sun protection remains imperative, as May showcases a higher UV index.Temperature
The onset of May marks a slight increase in the average high-temperature, moving from an agreeable 20.2°C (68.4°F) in April to a warm 23.5°C (74.3°F). Heraklion, during the month of May, experiences an average low-temperature of 15.9°C (60.6°F).Rainfall
In Heraklion, in May, during 1.9 rainfall days, 15mm (0.59") of precipitation is typically accumulated. In Heraklion, during the entire year, the rain falls for 53.2 days and collects up to 501mm (19.72") of precipitation.Sea temperature
In Heraklion, in May, the average water temperature is 19.5°C (67.1°F).Note: Most people find it challenging to enjoy swimming in water that is 19.5°C (67.1°F). As water temperature falls below 21°C (69.8°F), controlling breathing grows increasingly difficult.
Daylight
In May, the average length of the day is 14h and 2min.On the first day of the month, sunrise is at 06:27 and sunset at 20:05. On the last day of May, sunrise is at 06:05 and sunset at 20:28 EEST.
Sunshine
In Heraklion, the average sunshine in May is 9.7h.UV index
In Heraklion, the average daily maximum UV index in May is 9. A UV Index reading of 8 to 10 represents a very high health vulnerability from unsafe exposure to UV radiation for the average person.Note: An average UV index of 9 in May transforms into this advice:
Don't neglect protection; skin and eyes can be burned swiftly if left exposed. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Heraklion, Greece
- Average high temperature in May: 23.5°C
The warmest month (with the highest average high temperature) is July (28.6°C).
The month with the lowest average high temperature is January (15.2°C).
- Average low temperature in May: 15.9°C
The months with the highest average low temperature are July and August (22.7°C).
The coldest months (with the lowest average low temperature) are January and February (10°C).
Average rainfall in May
Heraklion, Greece
- Average rainfall in May: 15.2mm
The wettest month (with the highest rainfall) is January (91.5mm).
The driest month (with the least rainfall) is August (0.7mm).
Average rainfall days in May
Heraklion, Greece
- Average rainfall days in May: 1.9 days
The month with the highest number of rainy days is January (10.1 days).
The months with the least rainy days are July and August (0.1 days).
Average sea temperature in May
Heraklion, Greece
- Average sea temperature in May: 19.5°C
The best month for swimming (with the highest average sea temperature) is August (26.1°C).
The coldest month (with the lowest average sea temperature) is February (16.4°C).
Average daylight in May /
Average sunshine in May
Heraklion, Greece
- Average daylight in May: 14h and 0min
The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).
- Average sunshine in May: 9h and 42min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average UV index in May
Heraklion, Greece
- Average UV index in May: 9
The month with the highest UV index is July (UV index 11).
The month with the lowest UV index is December (UV index 2).





