worldweatherIran weather in May - temperature, rain and is it a good time to visit?
Weather in May at a glance
- Daytime temperature
- 29°C
- Night-time temperature
- 15°C
- Daylight hours
- 14h02min
- Chance of rain
- 29%
- Days with thunderstorms
- 17%
An overview for the country. Conditions can vary between cities and regions.
Iran in May: weather for a week away
Compare destinations and see how many days of a typical trip met your preferred temperature range, with less than 1 mm of daily precipitation.
No matching destination.
Tehran in May: Sightseeing
1981-2025Daytime temperature 18-28°CDaily precipitation Less than 1 mm
Weekly average; typical number of days: 0-4
of historical weeks
of historical weeks
How many matching days were there in a week?
Each bar shows the share of historical weeks.
When to go? Compare the months
Average matching days per weekThe highest average was in April: 4.6 matching days per week.
Iran in May: which destinations match most often?
Comparison of 10 cities and regions using your selected conditions.
Hot days and warm nights in May
Does the temperature drop below 20°C during hot weather?
On 6% of hot days, the temperature stayed at or above 20°C even at its coolest. This covers 587 days with a maximum of at least 30°C.
Lowest temperature on hot days
* A warm night is represented by the daily minimum ≥20°C. Maximum and minimum refer to the same day; this does not isolate the night following a particular hot day.
How much can temperatures change during a week?
Check cooler hours as well as afternoon temperatures.
How often does it get cooler from one day to the next?
14%of weeks with a day-to-day drop in maximum temperature of at least 5°C
A warmer layer may be useful in the evening and early morning. Weekly lows often differed greatly from afternoon temperatures.
Ranges are the 20th-80th percentiles of whole-week minima and maxima, not forecast limits. Cooling compares consecutive daily maxima, not day and night temperatures.
Compare all destinations
| City or region | Days matching your plans | At least 5 matching days | All 7 days match |
|---|---|---|---|
| Tehran | 2.1 / 7 | 16% | 3% |
| Ahvaz | 0 / 7 | 0% | 0% |
| Mashhad | 4 / 7 | 39% | 9% |
| Tabriz | 4.1 / 7 | 48% | 13% |
| Shiraz | 1.4 / 7 | 10% | 2% |
| Kerman | 2.1 / 7 | 18% | 4% |
| Karaj | 3.4 / 7 | 39% | 15% |
| Rasht | 4.6 / 7 | 58% | 13% |
| Esfahan | 2 / 7 | 17% | 4% |
| Qom | 1.7 / 7 | 8% | <1% |
Where do the figures come from?
The analysis includes 1,125 complete 7-day periods out of 1,125 possible periods in 45 years (1981-2025), for Tehran. Every week lies entirely within the selected month. Overlapping weeks are not independent samples. Incomplete weeks are excluded.
A matching day has a daily maximum within the selected temperature range, inclusive, and precipitation below 1 mm. Trace precipitation is possible. The typical range is the 20th-80th percentile of matching days per week. Daily percentages count each calendar day once; categories can overlap.
NASA POWER provides daily MERRA-2 grid data for each location, not city weather-station measurements or an area-wide country average. These are historical frequencies, not a forecast or a measure of forecast accuracy. This comparison does not include cloud, wind, humidity, sea temperature or changes within the day, and does not assess outdoor safety. Check the current forecast before travelling. NASA POWER Daily API.
Historical frequency, not a forecast for your travel dates.
Weather in Iran in May: trends from 1981 to 2025
From 2016 to 2025, the average daytime high was 28.8°C, 0.7°C warmer than in 1981-1990. 2025 was the warmest (32.3°C), while 1992 was the coolest (24°C).
How similar is the weather in May from year to year?
In 90% of the years compared, temperature and the number of wet days were close to typical for this month.
Similar means an average daily maximum within 2°C and a wet-day count within 3 days of the 1991-2020 medians. This is historical similarity, not forecast accuracy.Daytime temperatures in May: year by year
Monthly average daily maximum temperature: compare individual years and the longer-term trend.
Blue band: the 20th-80th percentile of monthly averages in 1991-2020. The thicker line is the average of five consecutive years. Highlights describe whole months, not single-day records.
View temperatures for every year
| Year | Average daytime maximum | 5-year average |
|---|---|---|
| 1981 | 25.8°C | - |
| 1982 | 28.1°C | - |
| 1983 | 28.7°C | - |
| 1984 | 24.9°C | - |
| 1985 | 28.2°C | 27.1°C |
| 1986 | 27.5°C | 27.5°C |
| 1987 | 29.2°C | 27.7°C |
| 1988 | 29.4°C | 27.8°C |
| 1989 | 28°C | 28.5°C |
| 1990 | 30.3°C | 28.9°C |
| 1991 | 27.3°C | 28.8°C |
| 1992 | 24°C | 27.8°C |
| 1993 | 26.5°C | 27.2°C |
| 1994 | 28.1°C | 27.2°C |
| 1995 | 26.5°C | 26.5°C |
| 1996 | 27.1°C | 26.4°C |
| 1997 | 27°C | 27°C |
| 1998 | 27.7°C | 27.3°C |
| 1999 | 30°C | 27.7°C |
| 2000 | 31.8°C | 28.7°C |
| 2001 | 30.8°C | 29.5°C |
| 2002 | 28.6°C | 29.8°C |
| 2003 | 27.2°C | 29.7°C |
| 2004 | 28°C | 29.3°C |
| 2005 | 27.4°C | 28.4°C |
| 2006 | 29.7°C | 28.2°C |
| 2007 | 27.7°C | 28°C |
| 2008 | 29.8°C | 28.5°C |
| 2009 | 28°C | 28.5°C |
| 2010 | 28.8°C | 28.8°C |
| 2011 | 29.5°C | 28.8°C |
| 2012 | 29.2°C | 29.1°C |
| 2013 | 26.7°C | 28.4°C |
| 2014 | 28.3°C | 28.5°C |
| 2015 | 29.5°C | 28.6°C |
| 2016 | 30°C | 28.7°C |
| 2017 | 29.6°C | 28.8°C |
| 2018 | 26.4°C | 28.8°C |
| 2019 | 27.5°C | 28.6°C |
| 2020 | 27.7°C | 28.2°C |
| 2021 | 29.3°C | 28.1°C |
| 2022 | 28.4°C | 27.9°C |
| 2023 | 29.1°C | 28.4°C |
| 2024 | 27.2°C | 28.3°C |
| 2025 | 32.3°C | 29.3°C |
How has May changed since the 1980s?
A comparison of 1981-1990 with 2016-2025 shows how temperatures, rainfall and the frequency of longer hot spells have changed.
In the latest decade, the average daytime high was 0.7°C warmer than in 1981-1990.
How often does May bring heat, frost and rain?
Typical number of days and monthly precipitation based on the 1991-2020 climate normal.
How often does it rain in Iran in May?
The chances use every consecutive 3-, 5- and 7-day period from 1981 to 2025. A wet day has at least 1 mm of precipitation.
A full seven days without rain occurred in 85% of historical periods. At least one wet day occurred in 15% of weeks.
Heatwaves, warm nights and cool spells in May
The percentages show years with at least one run of three consecutive days or nights meeting the stated threshold.
Highest and lowest values since 1981
Start, middle or end of the month - when is the weather most stable?
We compare temperatures, dry days, heavy rain and wind. The highlighted period usually has the lowest combined risk of rain and stronger winds.
- Dry days
- 9 days
- Heavy-rain risk
- 0%
- Hot days
- 5%
- Stronger wind
- 0%
- Dry days
- 10 days
- Heavy-rain risk
- 0%
- Hot days
- 29%
- Stronger wind
- 0%
- Dry days
- 11 days
- Heavy-rain risk
- 0%
- Hot days
- 63%
- Stronger wind
- 0%
The most stable conditions for rain and wind usually occur during: Days 11-20.
Country values are the median of data for 10 cities covered by the site. Source: NASA POWER daily gridded data (MERRA-2), 1981-2025; 1991-2020 climate normal. These are area-based model data and can differ from official weather-station records.
Iran weather all year - average temperatures and rain
| Month | Day | Night | Chance of rain |
|---|---|---|---|
| January | 11℃ | 0℃ | 16% |
| February | 12℃ | 2℃ | 23% |
| March ★ | 17℃ | 6℃ | 33% |
| April ★ | 23℃ | 10℃ | 32% |
| May ★ | 29℃ | 15℃ | 29% |
| June | 35℃ | 20℃ | 8% |
| July | 37℃ | 22℃ | 5% |
| August | 35℃ | 21℃ | 2% |
| September ★ | 32℃ | 15℃ | 4% |
| October ★ | 24℃ | 10℃ | 11% |
| November ★ | 16℃ | 4℃ | 23% |
| December | 11℃ | 1℃ | 16% |
Where is it warmest in Iran in May? Weather by city
For each city, we show the average daytime temperature and the warmest and coolest year. The comparison uses the average daily high across the whole of May, not a single extreme day.
| Place | Day | Night | May 1981-2025 | Chance of rain |
|---|---|---|---|---|
| Qom | 33℃ | 19℃ |
Average29.6°C
Warmest year2025 · 33.8°C
Coolest year1992 · 24.7°C
Warmest day39.8°C · 20 May 2025
Coolest day13.3°C · 2 May 1992
| 4% |
| Shiraz | 31℃ | 14℃ |
Average30.2°C
Warmest year2025 · 33.7°C
Coolest year1992 · 27°C
Warmest day38.7°C · 23 May 2025
Coolest day17.8°C · 12 May 1985
| 13% |
| Kerman | 31℃ | 13℃ |
Average29.1°C
Warmest year2000 · 33.2°C
Coolest year1992 · 25.5°C
Warmest day37.4°C · 24 May 2025
Coolest day15.8°C · 1 May 1989
| 11% |
| Tehran | 29℃ | 18℃ |
Average28.9°C
Warmest year2025 · 33.3°C
Coolest year1992 · 24.2°C
Warmest day38.6°C · 21 May 2025
Coolest day13.6°C · 2 May 1992
| 37% |
| Mashhad | 29℃ | 15℃ |
Average25.2°C
Warmest year2000 · 29.8°C
Coolest year1992 · 19.7°C
Warmest day36.2°C · 16 May 2001
Coolest day9.4°C · 1 May 1989
| 29% |
| Karaj | 29℃ | 18℃ |
Average17.9°C
Warmest year2025 · 21.2°C
Coolest year1984 · 13.7°C
Warmest day26.9°C · 31 May 1999
Coolest day5.9°C · 6 May 1992
| 37% |
| Esfahan | 29℃ | 12℃ |
Average29.2°C
Warmest year2025 · 33.3°C
Coolest year1992 · 25.7°C
Warmest day37.9°C · 22 May 2025
Coolest day17.5°C · 5 May 1997
| 7% |
| Rasht | 25℃ | 16℃ |
Average22.6°C
Warmest year2012 · 25.9°C
Coolest year1992 · 18.4°C
Warmest day34.7°C · 30 May 2021
Coolest day8.4°C · 4 May 1992
| 31% |
| Tabriz | 24℃ | 11℃ |
Average20.3°C
Warmest year2021 · 23.3°C
Coolest year1984 · 15.2°C
Warmest day30.3°C · 30 May 1999
Coolest day5.6°C · 1 May 1981
| 47% |
Temperature records in Iran: May compared with the whole year
The comparison uses daily high temperatures from 1981-2025 for the 9 cities shown in the table.
These are records in NASA POWER gridded data for the analysed cities, not official national weather-station records.