Climate averages 1991–2020
Guidonia Montecelio weather
in May.
A warm, moderately wet month: the 5th warmest and the joint 5th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
May is a warm month in Guidonia Montecelio: daytime highs average 22.9°C and nights cool to about 11.5°C. By daytime temperature it is the 5th warmest of the 12 months.
Expect about 77 mm of rain on roughly 10 days, which makes May a moderately wet month (the joint 5th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 14 h 32 min on an average May day.
The nearest other city in this atlas is Rome (21 km away). In May its highs average 22.3°C, 0.6°C cooler than Guidonia Montecelio, with 58 mm of rain.
Among the 79 cities listed in Italy, Guidonia Montecelio ranks joint 10th of 79 for the warmest May highs and 48th of 79 for the driest May (rainfall, lowest first). The mean May high of those 79 cities is 21.8°C; Guidonia Montecelio is 1.1°C warmer than that mean.
From May to June, average highs rise by 4.8°C to 27.7°C, and monthly rainfall falls from 77 mm to 46 mm.
The annual picture
May in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Guidonia Montecelio climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 11.1°C2.0°C | 2.0°C | 69 | 8.5 | 9.59 h |
| February | 12.1°C2.1°C | 2.1°C | 77 | 9.4 | 10.611 h |
| March | 15.2°C4.5°C | 4.5°C | 84 | 9.9 | 11.912 h |
| April | 18.4°C7.4°C | 7.4°C | 94 | 12.2 | 13.313 h |
| May, selected | 22.9°C11.5°C | 11.5°C | 77 | 10.3 | 14.515 h |
| June | 27.7°C15.5°C | 15.5°C | 46 | 7.3 | 15.215 h |
| July | 31.1°C18.4°C | 18.4°C | 28 | 4.8 | 14.915 h |
| August | 31.5°C19.0°C | 19.0°C | 28 | 5.5 | 13.914 h |
| September | 25.7°C15.3°C | 15.3°C | 85 | 9.4 | 12.513 h |
| October | 20.9°C11.6°C | 11.6°C | 113 | 10.4 | 11.111 h |
| November | 15.8°C7.4°C | 7.4°C | 132 | 12.4 | 9.910 h |
| December | 11.9°C3.3°C | 3.3°C | 104 | 10.3 | 9.29 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
May in nearby cities
- Rome in MayItaly · 21 kmHigh 22.3°C · Low 12.5°C · 58 mm rain
- Acilia-Castel Fusano-Ostia Antica in MayItaly · 41 kmHigh 20.8°C · Low 14.5°C · 40 mm rain
- Aprilia in MayItaly · 45 kmHigh 21.1°C · Low 13.5°C · 53 mm rain
- Fiumicino in MayItaly · 47 kmHigh 20.6°C · Low 14.7°C · 40 mm rain
- Latina in MayItaly · 61 kmHigh 21.8°C · Low 13.4°C · 65 mm rain
- Terni in MayItaly · 64 kmHigh 22.9°C · Low 11.4°C · 83 mm rain
- Perugia in MayItaly · 127 kmHigh 20.1°C · Low 9.3°C · 69 mm rain
- Pescara in MayItaly · 132 kmHigh 21.4°C · Low 13.4°C · 54 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Guidonia Montecelio) is explained once on the Guidonia Montecelio year overview and on the Sources, method and limits page.