Avg High
Hanoi in May
Avg Low
Rain
Daylight
13h
What to expect
May in Hanoi is late spring, a shoulder-season window, so you can get a bit of variety across the month. It can feel distinctly hot through the middle of the day, with a noticeable cool-down after sunset. There is plenty of daylight to stretch outdoor time. Most days feel close to what the averages suggest, with straightforward pacing.
May in context
How it compares to the rest of the year in Hanoi.
Hottest (avg)
#4 / 12
Wettest (avg)
#4 / 12
Daylight Hours
#3 / 12
Windiest (avg)
#3 / 12
Highest UV
#1 / 12
Most Humid
#5 / 12
Monthly climate breakdown
Temperature
- Daytime high
-
- Nighttime low
-
- Feels like (avg)
-
Sunshine
- Daylight hours
- 13.1 h
- UV index (max)
- 9
- Typical sun hours
- 05:18 - 18:27
Rain & Snow
- Total rain
-
- Rainy days
- 20 days
- Cloud cover (avg)
- 76%
Humidity & Wind
- Humidity (avg)
- 81%
- Wind (avg)
-
- Wind (max gusts)
-
Daily climate explorer
Day 15 selected for May. Typical high 31.0°C and low 25.0°C.
Typical disruptions in May
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in May.
Humidity High impact
Muggy days Measures: Muggy days (dew point >=20C). Observed about 90% of days (28.0 days/month) in May. Historical risk signal only, not a day-by-day forecast.
28.0 days / month
~90% of days
Why this matters
- Expected days 28.0 days / month
- Probability ~90% of days
- Intensity Up to ~26°C (P95)
Muggy conditions are possible on ~28 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Heat High impact
Hot feels-like days Measures: Hot feels-like days (>=32C). Observed about 86% of days (26.5 days/month) in May. Historical risk signal only, not a day-by-day forecast.
26.5 days / month
~86% of days
Why this matters
- Expected days 26.5 days / month
- Probability ~86% of days
- Intensity Up to ~44°C (P95)
Feels-like heat >=32C is possible on ~27 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat High impact
Very hot feels-like Measures: Very hot feels-like days (>=35C). Observed about 70% of days (21.5 days/month) in May. Historical risk signal only, not a day-by-day forecast.
21.5 days / month
~70% of days
Why this matters
- Expected days 21.5 days / month
- Probability ~70% of days
- Intensity Up to ~44°C (P95)
Very hot feels-like conditions are possible on ~22 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat High impact
Heat stress risk Measures: High heat stress days. Observed about 69% of days (21.5 days/month) in May. Historical risk signal only, not a day-by-day forecast.
21.5 days / month
~69% of days
Why this matters
- Expected days 21.5 days / month
- Probability ~69% of days
- Intensity Up to ~44°C (P95)
Heat stress is possible on ~21 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat High impact
Hot days Measures: Hot days (>=30C). Observed about 69% of days (21.3 days/month) in May. Historical risk signal only, not a day-by-day forecast.
21.3 days / month
~69% of days
Why this matters
- Expected days 21.3 days / month
- Probability ~69% of days
- Intensity Up to ~37°C (P95)
Hot days are possible on ~21 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Humidity High impact
Oppressive humidity Measures: Oppressive humidity days (dew point >=24C). Observed about 59% of days (18.4 days/month) in May. Historical risk signal only, not a day-by-day forecast.
18.4 days / month
~59% of days
Why this matters
- Expected days 18.4 days / month
- Probability ~59% of days
- Intensity Up to ~26°C (P95)
Oppressive humidity is possible on ~18 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Show all disruptions (23 more)
Rain High impact
Rain disruption Measures: Likely rain disruption days. Observed about 36% of days (11.3 days/month) in May. Historical risk signal only, not a day-by-day forecast.
11.3 days / month
~36% of days
Why this matters
- Expected days 11.3 days / month
- Probability ~36% of days
- Intensity Up to ~42mm (P95)
Rain disruption risk appears on ~11 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain High impact
Washout risk Measures: Washout day risk. Observed about 34% of days (10.4 days/month) in May. Historical risk signal only, not a day-by-day forecast.
10.4 days / month
~34% of days
Why this matters
- Expected days 10.4 days / month
- Probability ~34% of days
- Intensity Up to ~43mm (P95)
Washout conditions are possible on ~10 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain High impact
Heavy rain days Measures: Heavy rain days (>=10mm). Observed about 26% of days (8.0 days/month) in May. Historical risk signal only, not a day-by-day forecast.
8.0 days / month
~26% of days
Why this matters
- Expected days 8.0 days / month
- Probability ~26% of days
- Intensity Up to ~46mm (P95)
Heavy rain is possible on ~8 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Heat High impact
Very hot days Measures: Very hot days (>=35C). Observed about 12% of days (3.9 days/month) in May. Historical risk signal only, not a day-by-day forecast.
3.9 days / month
~12% of days
Why this matters
- Expected days 3.9 days / month
- Probability ~12% of days
- Intensity Up to ~38°C (P95)
Very hot days are possible on ~4 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Rain High impact
Washout run Measures: Multi-day washout runs. Observed about 2.8 days/month in May. Historical risk signal only, not a day-by-day forecast.
2.8 days / month
Probability unavailable
Why this matters
- Expected days 2.8 days / month
- Probability —
- Intensity Up to ~53mm (P95)
Multi-day washout runs are possible on ~3 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain High impact
Very heavy rain Measures: Very heavy rain days (>=25mm). Observed about 9% of days (2.7 days/month) in May. Historical risk signal only, not a day-by-day forecast.
2.7 days / month
~9% of days
Why this matters
- Expected days 2.7 days / month
- Probability ~9% of days
- Intensity Up to ~71mm (P95)
Very heavy rain is possible on ~3 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Heat High impact
Feels-like heatwave Measures: Feels-like heatwave runs (>=3 days). Observed about 2.5 days/month in May. Historical risk signal only, not a day-by-day forecast.
2.5 days / month
Probability unavailable
Why this matters
- Expected days 2.5 days / month
- Probability —
- Intensity Up to ~44°C (P95)
Feels-like heatwave runs are possible on ~2 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Rain High impact
Extreme rain Measures: Extreme rain days (>=50mm). Observed about 1% of days (0.4 days/month) in May. Historical risk signal only, not a day-by-day forecast.
0.4 days / month
~1% of days
Why this matters
- Expected days 0.4 days / month
- Probability ~1% of days
- Intensity Up to ~141mm (P95)
Extreme rain is possible on ~0 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Heat Moderate
Heatwave run Measures: Heatwave runs (>=3 hot days). Observed about 2.8 days/month in May. Historical risk signal only, not a day-by-day forecast.
2.8 days / month
Probability unavailable
Why this matters
- Expected days 2.8 days / month
- Probability —
- Intensity Up to ~36°C (P95)
Heatwave runs are possible on ~3 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Visibility Moderate
Fog-likely signal Measures: Fog-likely visibility proxy. Observed about 9% of days (2.7 days/month) in May. Historical risk signal only, not a day-by-day forecast.
2.7 days / month
~9% of days
Why this matters
- Expected days 2.7 days / month
- Probability ~9% of days
- Intensity Up to ~95% (P95)
Fog-likely conditions are possible on ~3 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Humidity Minor
Humid days Measures: Humid days (dew point >=18C). Observed about 97% of days (30.0 days/month) in May. Historical risk signal only, not a day-by-day forecast.
30.0 days / month
~97% of days
Why this matters
- Expected days 30.0 days / month
- Probability ~97% of days
- Intensity Up to ~26°C (P95)
Humid conditions are possible on ~30 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Heat Minor
Warm nights Measures: Warm nights (min >=22C). Observed about 85% of days (26.4 days/month) in May. Historical risk signal only, not a day-by-day forecast.
26.4 days / month
~85% of days
Why this matters
- Expected days 26.4 days / month
- Probability ~85% of days
- Intensity Up to ~27°C (P95)
Warm nights are possible on ~26 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cloud Minor
Cloudy days Measures: Cloudy days (cloud cover >=60%). Observed about 75% of days (23.4 days/month) in May. Historical risk signal only, not a day-by-day forecast.
23.4 days / month
~75% of days
Why this matters
- Expected days 23.4 days / month
- Probability ~75% of days
- Intensity Up to ~100% (P95)
Cloudy skies are possible on ~23 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rain Minor
Wet days Measures: Wet days (>=0.1mm). Observed about 72% of days (22.5 days/month) in May. Historical risk signal only, not a day-by-day forecast.
22.5 days / month
~72% of days
Why this matters
- Expected days 22.5 days / month
- Probability ~72% of days
- Intensity Up to ~33mm (P95)
Measurable rain is possible on ~22 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Humidity Minor
High humidity Measures: High humidity days (RH >=80%). Observed about 66% of days (20.3 days/month) in May. Historical risk signal only, not a day-by-day forecast.
20.3 days / month
~66% of days
Why this matters
- Expected days 20.3 days / month
- Probability ~66% of days
- Intensity Up to ~92% (P95)
High humidity is possible on ~20 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Rain Minor
Rainy hours Measures: Rain-hours signal (>=3h rain). Observed about 60% of days (18.7 days/month) in May. Historical risk signal only, not a day-by-day forecast.
18.7 days / month
~60% of days
Why this matters
- Expected days 18.7 days / month
- Probability ~60% of days
- Intensity Up to ~21h (P95)
Several rainy hours are possible on ~19 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Cloud Minor
Mostly cloudy days Measures: Mostly cloudy days (cloud cover >=80%). Observed about 56% of days (17.4 days/month) in May. Historical risk signal only, not a day-by-day forecast.
17.4 days / month
~56% of days
Why this matters
- Expected days 17.4 days / month
- Probability ~56% of days
- Intensity Up to ~100% (P95)
Mostly cloudy skies are possible on ~17 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rain Minor
Wet most of day Measures: Wet-most-of-day signal (>=6h rain). Observed about 47% of days (14.6 days/month) in May. Historical risk signal only, not a day-by-day forecast.
14.6 days / month
~47% of days
Why this matters
- Expected days 14.6 days / month
- Probability ~47% of days
- Intensity Up to ~21h (P95)
Wet-most-of-day conditions are possible on ~15 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Heat Minor
Hot nights Measures: Hot nights (min >=25C). Observed about 44% of days (13.7 days/month) in May. Historical risk signal only, not a day-by-day forecast.
13.7 days / month
~44% of days
Why this matters
- Expected days 13.7 days / month
- Probability ~44% of days
- Intensity Up to ~28°C (P95)
Hot nights are possible on ~14 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Humidity Minor
Convective risk Measures: Convective storm risk proxy. Observed about 36% of days (11.2 days/month) in May. Historical risk signal only, not a day-by-day forecast.
11.2 days / month
~36% of days
Why this matters
- Expected days 11.2 days / month
- Probability ~36% of days
- Intensity Up to ~26°C (P95)
Convective risk signal appears on ~11 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cloud Minor
Overcast days Measures: Overcast days (cloud cover >=95%). Observed about 33% of days (10.1 days/month) in May. Historical risk signal only, not a day-by-day forecast.
10.1 days / month
~33% of days
Why this matters
- Expected days 10.1 days / month
- Probability ~33% of days
- Intensity Up to ~100% (P95)
Overcast skies are possible on ~10 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Other Minor
Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data Measures: Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data. Observed about 9% of days (2.7 days/month) in May. Historical risk signal only, not a day-by-day forecast.
2.7 days / month
~9% of days
Why this matters
- Expected days 2.7 days / month
- Probability ~9% of days
- Intensity Up to ~95 (P95)
Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data is possible on ~3 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Wind Minor
Gusty days Measures: Gusty days (>=40 km/h). Observed about 4% of days (1.3 days/month) in May. Historical risk signal only, not a day-by-day forecast.
1.3 days / month
~4% of days
Why this matters
- Expected days 1.3 days / month
- Probability ~4% of days
- Intensity Up to ~50km/h (P95)
Gusty conditions are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Frequently asked questions
Is May a good time to visit Hanoi?
Typical May days in Hanoi reach highs of 31°C (88°F) with nights around 24°C (75°F). It usually feels hot by day and warm after dark. Overall, May sits in the middle of the Hanoi climate range.
What are temperatures like in May?
Daytime temperatures in May typically peak near 31°C (88°F), while nights drop to around 24°C (75°F). Expect hot afternoons and warm evenings.
How much does it rain in May?
Rainfall in May averages 233 mm (9.2 in) across roughly 20 days. Overall it is a very wet time of year, so a light rain jacket and waterproof shoes are very handy.
How many hours of daylight are there in May?
You can expect about 13 hours of daylight in May. Sunrise is typically around 05:18 and sunset near 18:27. You get long days with comfortable amounts of daylight.
How strong is the sun in May?
UV levels frequently reach very high levels (around 9), so strong sun protection is essential, especially around midday.
Is it windy in May?
In May, average wind speeds are around 9 km/h (6 mph), with gusts on the windiest days reaching about 36 km/h (22 mph). On the ground, it is a gentle to moderate breeze is common, but stronger winds are not frequent.