United States, Yosemite National Park

Monday

Today

Moderate

Tuesday

Tomorrow

High

Wednesday

Jun 18

Extreme

Thursday

Jun 19

High

Friday

Jun 20

Moderate

How we forecast?

Yosemite National Park Mosquito Forecast

If you're planning a trip to Yosemite National Park, knowing the mosquito forecast can make a big difference in your outdoor experience. The Yosemite National Park mosquito forecast indicates peak mosquito activity typically occurs from June through August, with July being the most intense month. During these summer months, especially near Yosemite Valley and the Merced River, expect mosquito levels to be around 8 to 9 on a scale of 1 to 10. Early spring and late fall see much lower activity, making those times ideal for visitors sensitive to insect bites. For real-time updates, check the National Park Service's mosquito alerts before your visit to plan accordingly.

Year round mosquito forecast

Mosquito Intensity

What Influences Mosquito Activity in Yosemite?

Mosquito populations in Yosemite are influenced by a mix of environmental factors unique to the Sierra Nevada region. The park's numerous water sources, including the Merced River and alpine lakes, provide perfect breeding grounds. Warm temperatures combined with recent rainfall can cause a surge in mosquito numbers. Yosemite's elevation also plays a role; lower elevations like Yosemite Valley experience more mosquitoes compared to higher altitudes such as Tuolumne Meadows. Key factors include:

Standing water availability
Temperature and humidity levels
Seasonal rainfall patterns

Understanding these influences helps visitors anticipate mosquito presence and take preventive steps during their stay.

Mosquito-Borne Diseases in Yosemite National Park

While mosquitoes in Yosemite National Park are common, the risk of mosquito-borne diseases remains relatively low. However, visitors should be aware of potential illnesses such as West Nile Virus, which has been reported sporadically in California. The park's wildlife, including birds and small mammals, can act as reservoirs for these viruses. To minimize risk, it's important to:

Use insect repellent containing DEET or picaridin
Wear long sleeves and pants during dawn and dusk
Avoid heavily infested areas when possible

For more detailed health advisories, visit the California Department of Public Health website.

Stay Updated and Prepared for Yosemite Mosquito Season

Keeping up with the latest mosquito activity and taking preventive measures can ensure a comfortable visit to Yosemite National Park. Sign up for alerts from local health departments and check the Centers for Disease Control and Prevention (CDC) for updates on mosquito-borne disease outbreaks. Packing essentials like insect repellent, mosquito nets, and appropriate clothing can make a big difference. Remember, early morning and evening hours are peak mosquito times, so plan your hikes accordingly. Staying informed and prepared helps you enjoy Yosemite’s breathtaking views without the nuisance of mosquito bites. Stay safe and enjoy your adventure with the Yosemite National Park mosquito forecast in mind.

Check out our recommended mosquito protection products

Mosquito-borne diseases in the area

Malaria

Zika

Dengue

Yellow Fever

Chikungunya

West Nile Fever

FAQs

The peak mosquito season is from June to August, with July typically having the highest mosquito activity.

Mosquito-borne diseases are relatively rare in Yosemite, but visitors should still take precautions against illnesses like West Nile Virus.

Use insect repellent, wear long sleeves and pants during dawn and dusk, and avoid areas with standing water whenever possible.

Further information

Centers for Disease Control and PreventionNational Park ServiceCalifornia Department of Public Health