Hottest (avg)
#4 / 12
Sits around the middle of the year.
May in context
How it compares to the rest of the year in Hanoi.
Wettest (avg)
#4 / 12
Typical rainfall for the year.
Daylight Hours
#3 / 12
Long daylight hours.
Windiest (avg)
#3 / 12
Among the windier months.
Highest UV
#1 / 12
Peak UV levels for the year.
Most Humid
#5 / 12
Humidity stays close to the yearly norm.
Monthly climate breakdown
A detailed look at the typical climate conditions for May.
Thermal profile
Temperature
Typical daytime high
- Nighttime low
-
- Feels like (avg)
-
Light window
Sunshine
13.1 h
Average daylight
- UV index (max)
- 9
- Typical sun hours
- 05:18 - 18:27
Wet-day pattern
Rain & Snow
Typical rainfall
- Rainy days
- 20 days
- Cloud cover (avg)
- 76%
Air feel
Humidity & Wind
81%
Average humidity
- Wind (avg)
-
- Wind (max gusts)
-
Historical daily baseline
Daily climate explorer
Pick a day to inspect the usual conditions through May in Hanoi. Based on a 30-year historical climate baseline, not a forecast.
Primary control
Select a day
Scroll to compare daily conditions. The summary updates with your selection.
Secondary context
Monthly trend
Median daytime highs across the month, with a softer low line.
Median temperatureMedian lowTypical range
Day 15 selected for May. Temperature 31.0°C.
Historical disruption baseline
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.
Likely frequency
28.0 days / month
- Share of days
- ~90% of days
- Upper edge
- Up to ~26°C (P95)
Why this matters
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.
Likely frequency
26.5 days / month
- Share of days
- ~86% of days
- Upper edge
- Up to ~44°C (P95)
Why this matters
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.
Likely frequency
21.5 days / month
- Share of days
- ~70% of days
- Upper edge
- Up to ~44°C (P95)
Why this matters
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.
Likely frequency
21.5 days / month
- Share of days
- ~69% of days
- Upper edge
- Up to ~44°C (P95)
Why this matters
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.
Likely frequency
21.3 days / month
- Share of days
- ~69% of days
- Upper edge
- Up to ~37°C (P95)
Why this matters
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.
Likely frequency
18.4 days / month
- Share of days
- ~59% of days
- Upper edge
- Up to ~26°C (P95)
Why this matters
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.
Likely frequency
11.3 days / month
- Share of days
- ~36% of days
- Upper edge
- Up to ~42mm (P95)
Why this matters
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.
Likely frequency
10.4 days / month
- Share of days
- ~34% of days
- Upper edge
- Up to ~43mm (P95)
Why this matters
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.
Likely frequency
8.0 days / month
- Share of days
- ~26% of days
- Upper edge
- Up to ~46mm (P95)
Why this matters
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.
Likely frequency
3.9 days / month
- Share of days
- ~12% of days
- Upper edge
- Up to ~38°C (P95)
Why this matters
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.
Likely frequency
2.8 days / month
- Share of days
- —
- Upper edge
- Up to ~53mm (P95)
Why this matters
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.
Likely frequency
2.7 days / month
- Share of days
- ~9% of days
- Upper edge
- Up to ~71mm (P95)
Why this matters
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.
Likely frequency
2.5 days / month
- Share of days
- —
- Upper edge
- Up to ~44°C (P95)
Why this matters
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.
Likely frequency
0.4 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~141mm (P95)
Why this matters
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.
Likely frequency
2.8 days / month
- Share of days
- —
- Upper edge
- Up to ~36°C (P95)
Why this matters
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.
Likely frequency
2.7 days / month
- Share of days
- ~9% of days
- Upper edge
- Up to ~95% (P95)
Why this matters
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.
Likely frequency
30.0 days / month
- Share of days
- ~97% of days
- Upper edge
- Up to ~26°C (P95)
Why this matters
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.
Likely frequency
26.4 days / month
- Share of days
- ~85% of days
- Upper edge
- Up to ~27°C (P95)
Why this matters
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.
Likely frequency
23.4 days / month
- Share of days
- ~75% of days
- Upper edge
- Up to ~100% (P95)
Why this matters
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.
Likely frequency
22.5 days / month
- Share of days
- ~72% of days
- Upper edge
- Up to ~33mm (P95)
Why this matters
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.
Likely frequency
20.3 days / month
- Share of days
- ~66% of days
- Upper edge
- Up to ~92% (P95)
Why this matters
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.
Likely frequency
18.7 days / month
- Share of days
- ~60% of days
- Upper edge
- Up to ~21h (P95)
Why this matters
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.
Likely frequency
17.4 days / month
- Share of days
- ~56% of days
- Upper edge
- Up to ~100% (P95)
Why this matters
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.
Likely frequency
14.6 days / month
- Share of days
- ~47% of days
- Upper edge
- Up to ~21h (P95)
Why this matters
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.
Likely frequency
13.7 days / month
- Share of days
- ~44% of days
- Upper edge
- Up to ~28°C (P95)
Why this matters
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.
Likely frequency
11.2 days / month
- Share of days
- ~36% of days
- Upper edge
- Up to ~26°C (P95)
Why this matters
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.
Likely frequency
10.1 days / month
- Share of days
- ~33% of days
- Upper edge
- Up to ~100% (P95)
Why this matters
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.
Likely frequency
2.7 days / month
- Share of days
- ~9% of days
- Upper edge
- Up to ~95 (P95)
Why this matters
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.
Likely frequency
1.3 days / month
- Share of days
- ~4% of days
- Upper edge
- Up to ~50km/h (P95)
Why this matters
Gusty conditions are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Travel planning FAQ
Frequently asked questions
Quick answers to the weather questions you ask the most.
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.