St. Catharines
May
Weather in St. Catharines for May 2026
Your guide to St. Catharines weather in May - trends and predictions
In general, the average temperature in St. Catharines at the beginning of May is 12.6 °C. As the month progressed, temperatures tended to significantly warm up, reaching an average of 17.7 °C by the end of May.
St. Catharines experiences heavy rainfall in May, with over 20 rainy days and an average total precipitation 159.3 mm.
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Temperatures
Rain 🌧️
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10
Dry days
21
Rainy days
0
Snow days
16°/9°
Temperatures
21 km/h
Avg max wind
79 %
Avg humidity
St. Catharines Weather May
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Temperatures trend during May in St. Catharines
See the weather trend as well as the moving average line
May weather in St. Catharines day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 May |  Patchy rain possible | 11° /5° | 9.6 mm | 3 | |
| 2 May |  Heavy rain at times | 12° /7° | 8.1 mm | 3 | |
| 3 May |  Moderate rain at times | 11° /5° | 3.6 mm | 3 | |
| 4 May | Patchy rain possible | 11° /6° | 8 mm | 3 | |
| 5 May |  Overcast | 13° /7° | 0.5 mm | 3 | |
| 6 May |  Sunny | 15° /8° | 3.4 mm | 4 | |
| 7 May | Heavy rain at times | 15° /7° | 2.1 mm | 3 | |
| 8 May | Overcast | 15° /7° | 2 mm | 3 | |
| 9 May | Moderate or heavy rain shower | 12° /6° | 2.8 mm | 3 | |
| 10 May |  Partly cloudy | 15° /5° | 0.1 mm | 4 | |
| 11 May | Overcast | 15° /6° | 1.9 mm | 4 | |
| 12 May | Sunny | 18° /7° | 0.1 mm | 5 | |
| 13 May | Partly cloudy | 18° /11° | 11.1 mm | 4 | |
| 14 May |  Cloudy | 16° /11° | 9.2 mm | 4 | |
| 15 May | Sunny | 18° /10° | 1 mm | 5 | |
| 16 May | Overcast | 19° /10° | 27.3 mm | 4 | |
| 17 May | Sunny | 16° /9° | 5 mm | 4 | |
| 18 May | Sunny | 15° /8° | 0.1 mm | 4 | |
| 19 May | Overcast | 17° /9° | 0.7 mm | 4 | |
| 20 May | Moderate or heavy rain shower | 16° /9° | 10.9 mm | 4 | |
| 21 May | Sunny | 18° /10° | 11.9 mm | 5 | |
| 22 May | Partly cloudy | 17° /11° | 20.4 mm | 4 | |
| 23 May | Cloudy | 17° /10° | 0.1 mm | 4 | |
| 24 May | Moderate rain at times | 17° /9° | 0.4 mm | 4 | |
| 25 May | Sunny | 16° /8° | 3 mm | 4 | |
| 26 May | Sunny | 17° /8° | 0 mm | 5 | |
| 27 May | Sunny | 18° /10° | 1.3 mm | 4 | |
| 28 May | Sunny | 18° /11° | 1 mm | 4 | |
| 29 May | Sunny | 17° /11° | 13.6 mm | 4 | |
| 30 May | Sunny | 19° /11° | 0 mm | 5 | |
| 31 May | Sunny | 19° /11° | 0 mm | 5 | |
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Important Notice
Our weather forecast for St. Catharines in May is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the St. Catharines forecast closer to your planned date for the most up-to-date weather information.
Change Month
St. Catharines in May - FAQ
What are the expected maximum and minimum temperatures in St. Catharines during May?
Enjoy moderate daytime temperatures of up to 16° and cooler nights around 9°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in St. Catharines during May?
Significant rainfall exceeding 159.3 mm is expected in St. Catharines during May, occurring over more than 21 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in St. Catharines during May?
The average wind speed in St. Catharines during May is 21 km/h, suggesting breezy to windy conditions, depending on your activities.
May rainfall patterns in St. Catharines
Explore the daily rainfall trends and prepare for St. Cathariness May weather 💧
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Where is St. Catharines?Get accurate weather forecasts for St. Catharines, located at latitude 43.171 and longitude -79.243. Stay updated with localized weather information tailored for St. Catharines.
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