Ajax, Ontario Weather by Month and Climate Averages

Ajax, Ontario gets 724 mm of precipitation a year over about 121 rainy days. July is the warmest month (average high 27°C) and February the coldest (average low -10°C).

Ajax climate at a glance

Humid continental climate

Ajax, Ontario has warm summers and cold winters. Daytime highs range from about -1°C in February to 27°C in July. June is usually the wettest month. The most comfortable time to visit is typically May and August to September, when daytime highs sit near 22°C.

How much rain does Ajax get?

Ajax gets 724 mm of precipitation in an average year, spread over about 121 days with measurable rain. That is more rainy days than 51% of Canada.

June is the wettest month, with 82 mm. February is the driest, with 37 mm. October has the most rainy days, about 13.

The longest dry spell in the last five years lasted 17 days, to June 10, 2023.

Ajax weather by month

Ajax weather in January

In January, Ajax averages a high of -1°C and a low of -9°C. It gets 51 mm of precipitation over about 10 rainy days. The sun is out about 18% of daylight hours. The January record high is 12°C (2013) and the record low is -27°C (2018).

Ajax weather in February

In February, Ajax averages a high of -1°C and a low of -10°C. It gets 37 mm of precipitation over about 8 rainy days. The sun is out about 30% of daylight hours. The February record high is 18°C (2017) and the record low is -28°C (2023).

Ajax weather in March

In March, Ajax averages a high of 4°C and a low of -5°C. It gets 49 mm of precipitation over about 10 rainy days. The sun is out about 35% of daylight hours. The March record high is 23°C (2012) and the record low is -25°C (2015).

Ajax weather in April

In April, Ajax averages a high of 11°C and a low of 1°C. It gets 82 mm of precipitation over about 12 rainy days. The sun is out about 38% of daylight hours. The April record high is 27°C (2023) and the record low is -10°C (2016).

Ajax weather in May

In May, Ajax averages a high of 18°C and a low of 7°C. It gets 61 mm of precipitation over about 11 rainy days. The sun is out about 44% of daylight hours. The May record high is 31°C (2020) and the record low is -4°C (2020). May is one of the most comfortable months to visit.

Ajax weather in June

In June, Ajax averages a high of 24°C and a low of 13°C. It gets 82 mm of precipitation over about 10 rainy days. The sun is out about 47% of daylight hours. The June record high is 32°C (2012) and the record low is 2°C (2019).

Ajax weather in July

In July, Ajax averages a high of 27°C and a low of 16°C. It gets 61 mm of precipitation over about 9 rainy days. The sun is out about 51% of daylight hours. The July record high is 37°C (2011) and the record low is 8°C (2014).

Ajax weather in August

In August, Ajax averages a high of 26°C and a low of 14°C. It gets 70 mm of precipitation over about 9 rainy days. The sun is out about 49% of daylight hours. The August record high is 33°C (2016) and the record low is 7°C (2013). August is one of the most comfortable months to visit.

Ajax weather in September

In September, Ajax averages a high of 22°C and a low of 11°C. It gets 62 mm of precipitation over about 9 rainy days. The sun is out about 51% of daylight hours. The September record high is 32°C (2018) and the record low is 0°C (2020). September is one of the most comfortable months to visit.

Ajax weather in October

In October, Ajax averages a high of 14°C and a low of 4°C. It gets 74 mm of precipitation over about 13 rainy days. The sun is out about 40% of daylight hours. The October record high is 28°C (2019) and the record low is -7°C (2020).

Ajax weather in November

In November, Ajax averages a high of 7°C and a low of -2°C. It gets 45 mm of precipitation over about 10 rainy days. The sun is out about 38% of daylight hours. The November record high is 23°C (2022) and the record low is -17°C (2019).

Ajax weather in December

In December, Ajax averages a high of 2°C and a low of -6°C. It gets 50 mm of precipitation over about 12 rainy days. The sun is out about 20% of daylight hours. The December record high is 15°C (2021) and the record low is -27°C (2017).

Sunshine, humidity and wind in Ajax

July is the sunniest month in Ajax, with sunshine about 51% of daylight hours. January is the cloudiest, at 18%. Over the year the sun shines about 38% of daylight hours. Ajax is sunnier than 71% of Canada.

Humidity peaks in July at 79% and is lowest in February at 72%.

Ajax weather records

The hottest temperature on record at the Ajax station is 37°C, on July 21, 2011. The coldest is -28°C, on February 4, 2023.

The wettest day on record brought 59 mm of rain, on October 28, 2015.

The best time to visit Ajax

The most comfortable time to visit is typically May and August to September, when daytime highs sit near 22°C.

Winter (December–February) is cold, with average highs around 0°C and lows near -8°C.

Spring (March–May) is chilly, with average highs around 11°C and lows near 1°C.

Summer (June–August) is warm, with average highs around 25°C and lows near 14°C. It can feel humid.

Autumn (September–November) is mild, with average highs around 14°C and lows near 5°C.

Monthly climate

MonthPrecipRain daysHumiditySunshineSea tempRecord highRecord low
January51 mm1076%18%-16°12°-27°
February37 mm872%30%-17°18°-28°
March49 mm1073%35%-17°23°-25°
April82 mm1274%38%-16°27°-10°
May61 mm1176%44%-14°31°-4°
June82 mm1078%47%-10°32°
July61 mm979%51%-7°37°
August70 mm978%49%-6°33°
September62 mm975%51%-7°32°
October74 mm1374%40%-10°28°-7°
November45 mm1073%38%-13°23°-17°
December50 mm1276%20%-16°15°-27°

From ERA5 reanalysis. Sunshine is estimated from cloud cover.

Ajax climate questions

How much rain does Ajax get?

Ajax gets 724 mm of precipitation in an average year, over about 121 rainy days.

What is the wettest month in Ajax?

June is the wettest month in Ajax, with 82 mm. February is the driest, with 37 mm.

How many rainy days does Ajax have a year?

Ajax has about 121 days with measurable rain in an average year. October has the most, about 13.

What is the hottest month in Ajax?

July is the warmest month in Ajax, with an average high of 27°C.

What is the coldest month in Ajax?

February is the coldest month in Ajax, with an average low of -10°C.

What is the record high temperature in Ajax?

The record high at the Ajax station is 37°C, set on July 21, 2011. The record low is -28°C, on February 4, 2023.

What is the sunniest month in Ajax?

July is the sunniest month in Ajax, with sunshine about 51% of daylight hours. January is the cloudiest.

What is the best time to visit Ajax?

The most comfortable time to visit is typically May and August to September, when daytime highs sit near 22°C.

Source: NOAA GHCN-Daily station OSHAWA (14 km away).

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Normals from NOAA GHCN-Daily station OSHAWA.