When to go · Ontario, California
Ontario, California in June
Good month. Outside the best window (Mar–May, Sep–Nov). Across United States: Rockies and northern parks open; desert heat builds; hurricane season starts. Book parks months ahead.
Key facts
- Verdict
- Good
- Temperature
- 33°C (91°F)91°F (33°C) / 18°C (64°F)64°F (18°C)
- average high / low
- Rain days
- 1
- Crowds
- High
- United States overall
- Prices
- High
- United States overall
Verdict
Outside the best window (Mar–May, Sep–Nov). Across United States: Rockies and northern parks open; desert heat builds; hurricane season starts. Book parks months ahead.
Is another month better than June?
June is rated good. These months rate higher:
Weather in June
- Ontario, CaliforniaHighs around 33 °C (91 °F), lows around 18 °C (64 °F), rain on about 1 dayHighs around 91 °F (33 °C), lows around 64 °F (18 °C), rain on about 1 day
Crowds and prices
- Crowds · United States overall
- High
- Prices · United States overall
- High
United States overall: Rockies and northern parks open; desert heat builds; hurricane season starts. Book parks months ahead.
High-price month: see what to book ahead.
Compare two months
Weather, crowds and prices for any two months in Ontario, California, side by side.
Verdict
Jun: Good
Mar: Great (better)
Daytime high
Jun: 33 °C (91 °F)91 °F (33 °C)
Mar: 22 °C (72 °F)72 °F (22 °C)
Night low
Jun: 18 °C (64 °F)64 °F (18 °C)
Mar: 9 °C (48 °F)48 °F (9 °C)
Rain days
Jun: 1 (better)
Mar: 4
Crowds
Jun: High
Mar: Medium
Prices
Jun: High
Mar: Medium
Festivals listed
Jun: 0
Mar: 2
June: Outside the best window (Mar–May, Sep–Nov). Across United States: Rockies and northern parks open; desert heat builds; hurricane season starts. Book parks months ahead.
March: Inside Ontario, California's best window: Mar–May, Sep–Nov.
Ontario, California: figures are long-term averages from this guide, not a forecast.
What to pack
- Light, breathable clothes, a sun hat and sunscreen