Weather in Sapporo in April
Japan · 20-year averages, April
A hard month. April asks something of you. Go in knowing what. Highs sit at 9.6 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.
April ranks 7 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. Layers, and a genuinely waterproof outer — at 9.6 °C the difference between a good day and a miserable one is entirely down to what you are wearing.
What the averages hide
Averages flatten a month, and this one hides a few things: 11 nights fall below freezing. Across the twenty years measured, the hottest April day reached 23 °C and the coldest night fell to -6.8 °C, and the wettest single day dropped 35 mm — roughly 56% of the month's rain in one day.
April is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest April on record still delivered 103 mm against 17 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 62 mm average is a reasonable planning figure, not a promise.
Wind is light at 7.2 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 84%, which at 9.6 °C means damp rather than muggy — the kind of cold that gets into a coat and stays there.
How April sits in the year
The month is on the way up: 7.9 °C warmer than March, and May adds another 7.2 °C. Late in the month feels noticeably different from the start of it, which is worth knowing if the trip is short. Rain has already shifted: 5 days fewer than March had.
Daylight in April
13.4 hours of daylight, gaining 1.4 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 4.8 °C in April — 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
Shoulder. The value months — prices ease off and you get the place closer to itself.
Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.
April in Sapporo versus nearby
If Sapporo is one option among several, the nearby comparison is worth making. Sendai is a better bet in April — 5.2 °C warmer, 2 days more rain. Niigata is close enough to be a coin toss — 2.9 °C warmer, 2 days more rain.
So: April is a compromise. June is 35 points better and is what Sapporo is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.
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 April.
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