Climate almanac

Ontario

California, United States · 34.06°, -117.65°

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What is the weather like in Ontario in May?

In May, Ontario is typically 74°F (23°C) during the day and 55°F (13°C) at night. The month brings about 0.5 in (13 mm) of precipitation in total.

  • Average high74°F (23°C)
  • Average low55°F (13°C)
  • Precipitation0.5 in (13 mm)
  • Clear or mostly clear days17
  • Based on2016-2025 daily ERA5 reanalysis data (10-year normals)