Fullerton, California has a mild Mediterranean climate year-round.

Summers are short and warm with very dry and clear weather, while winters are long and cool with partly cloudy conditions.

Monthly Average Temperatures:

• January: High 66°F (19°C), Low 45°F (7°C)
• February: High 66°F (19°C), Low 48°F (9°C)
• March: High 68°F (20°C), Low 50°F (10°C)
• April: High 72°F (22°C), Low 53°F (12°C)
• May: High 75°F (24°C), Low 58°F (14°C)
• June: High 79°F (26°C), Low 62°F (17°C)
• July: High 84°F (29°C), Low 65°F (18°C)
• August: High 86°F (30°C), Low 66°F (19°C)
• September: High 84°F (29°C), Low 64°F (18°C)
• October: High 79°F (26°C), Low 58°F (14°C)
• November: High 73°F (23°C), Low 50°F (10°C)
• December: High 66°F (19°C), Low 45°F (7°C)

Monthly Average Precipitation:

• January: About 2.5 inches (63mm)
• February: About 2.6 inches (66mm)
• March: About 2.0 inches (51mm)
• April: About 0.8 inches (20mm)
• May: About 0.3 inches (8mm)
• June: About 0.1 inches (3mm)
• July: About 0.0 inches (1mm)
• August: About 0.1 inches (2mm)
• September: About 0.2 inches (5mm)
• October: About 0.5 inches (13mm)
• November: About 1.1 inches (28mm)
• December: About 1.9 inches (48mm)

The average annual precipitation is about 12.1 inches (308mm), mainly concentrated in the winter months.

Natural Disaster Information:

Fullerton is located in California and is at risk for earthquakes. It is important for residents to prepare for earthquakes and establish evacuation plans in case of emergencies. Additionally, during the summer, the risk of fires may increase due to hot and dry weather, so caution is advised. The risk of flooding is relatively low, but localized flooding may occur due to drainage issues during heavy rainfall.