Weather in Sapporo in May
Japan · 20-year averages, May
A good month. May works. It is not the peak, but nothing about it fights you. Highs average 16.8 °C, lows 7 °C, and rain falls on 11 days — nothing in the month is working against you.
May ranks 5 of 12 in Sapporo: past the worst of the year but short of June, which is the month to book if the dates are open.
Rain on 11 days, 2 of them heavy. Enough to need a plan B, not enough to need a plan around it. Pack for 16.8 °C days and 7 °C nights; the spread matters more here than any single number.
What the averages hide
The averages here are honest — no hidden extremes worth planning around. Across the twenty years measured, the hottest May day reached 29.7 °C and the coldest night fell to -1.2 °C, and the wettest single day dropped 36 mm — roughly 49% of the month's rain in one day.
May is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest May on record still delivered 109 mm against 42 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 74 mm average is a reasonable planning figure, not a promise.
Wind is light at 5.4 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 82%, high enough to notice on the warm days without dominating them.
How May sits in the year
The month is on the way up: 7.2 °C warmer than April, and June adds another 4.6 °C. Late in the month feels noticeably different from the start of it, which is worth knowing if the trip is short.
Daylight in May
14.6 hours of daylight, gaining 1.1 hours across the month. That is between Sapporo's extremes of 15.3 and 9 hours, so days are long enough not to constrain the plan.
Sea temperature
The sea sits at about 7.9 °C in May — too cold to swim without a wetsuit. The sea peaks at 20.5 °C in August and bottoms out at 3.5 °C — water lags the air by a month or two, which is why the best swimming often comes after the best weather.
How busy it gets
Busy. Popular without being frantic; book the things you care about, improvise the rest.
Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.
May in Sapporo versus nearby
If Sapporo is one option among several, the nearby comparison is worth making. Sendai is close enough to be a coin toss — 4.2 °C warmer, 1 day more rain. Niigata is close enough to be a coin toss — within a degree on temperature, 1 day more rain.
So: May works, with June the better month by 12 points if the dates can move. If they cannot, nothing here should stop you booking.
Every month in Sapporo
| Month | High °C | Low °C | Rain days | Rain mm | Humidity % | Daylight h | Sea °C | Score |
|---|---|---|---|---|---|---|---|---|
| January | -2.5 | -8.2 | 24 | 103 | 94 | 9.3 | 6.5 | 3 |
| February | -2 | -8.6 | 21 | 84 | 92 | 10.5 | 3.8 | 3 |
| March | 1.7 | -4.9 | 16 | 72 | 91 | 11.8 | 3.5 | 16 |
| April | 9.6 | 1.1 | 11 | 62 | 84 | 13.4 | 4.8 | 46 |
| May | 16.8 | 7 | 11 | 74 | 82 | 14.6 | 7.9 | 69 |
| June | 21.4 | 12 | 10 | 82 | 84 | 15.3 | 12.7 | 81 |
| July | 25 | 16.4 | 12 | 121 | 86 | 15.1 | 17 | 75 |
| August | 25.9 | 17.8 | 13 | 160 | 86 | 14 | 20.5 | 72 |
| September | 21.9 | 13.8 | 15 | 137 | 85 | 12.6 | 20.4 | 70 |
| October | 15.1 | 7.1 | 16 | 119 | 84 | 11.1 | 17.3 | 53 |
| November | 7.1 | 0.8 | 20 | 129 | 88 | 9.8 | 13.7 | 24 |
| December | -0.4 | -5.7 | 24 | 130 | 93 | 9 | 10.2 | 6 |
See all twelve months in Sapporo, or where else to go in May.
Planning the rest of the trip
- Flight time to Sapporo how long you are actually in the air
- Sapporo time zone and the difference from home
- Days until your trip count down to the departure date