Solar Production Faces Climate Challenges

Solar production fell across parts of the U.S. Midwest and Southeast in August. Canadian smoke drifted south and cut sunlight. At the same time, tropical systems over the Atlantic spread thick cloud cover across the Southeast. These patterns pushed monthly irradiance below average in many counties. 

How Smoke and Dust Dim the Sun

Smoke and dust add aerosols to the air. Aerosols scatter and absorb sunlight before it reaches the panels. So even on a day with few clouds, panels may see less direct light and make less power. Analysts tracked smoke from Canada across the U.S. and even over the Atlantic to Europe, where it lowered sunlight there, too. 

At a Glance: Regional Impacts

North America: Smoke and Storms

Solcast’s mapping shows how smoke pushed “east and south” across the continent. The firm’s clear-sky analyses also show up to 20% drops near Canadian fire zones, while stable air raised sunlight over parts of the West. A strong hurricane season added thick cloud shields along parts of the Gulf and Southeast, pulling output down further. 

By June and July, smoke lowered sunlight across Canada and the Eastern U.S. In some places, smoke’s haze cut clear-sky irradiance by around 10% compared with last year. The same plume reached Europe on strong upper winds. 

South America: A Winter of Fire

In July, Brazil’s winter wildfires surged well above a normal year. Smoke reduced sunlight in the south and southeast. Yet the north of Brazil saw brighter skies, and Chile and Argentina enjoyed stronger sun under a persistent high-pressure ridge, with boosts of up to 20%. 

Europe: Dust from the Sahara

Europe faced several Saharan dust events in June. These storms pushed fine particles north. Solar generation dropped by up to 20% for days at a time. Then the dust mixed out and conditions improved.

Asia: Monsoon Rains, Typhoons, and a Strong Ridge

Asia split sharply in July. India’s record monsoon dimmed sunlight by about 10% on average. Typhoon activity cut light in parts of Southeast Asia. But a strong subtropical ridge over East Asia cleared skies at times in China and Japan. 

Why This Matters for Owners and Planners

Smoke can cut power far from the fire line. It reduces direct light, increases diffuse light, and speeds up panel soiling. The U.S. Department of Energy’s Federal Energy Management Program (FEMP) notes that smoke has caused measured PV output losses from about 9.4% up to 37.8% at western U.S. sites, with even larger local drops during extreme events. 

Simple Resilience Steps (Plain-English)

• Create defensible space: Clear vegetation and fuels around arrays, inverters, and access roads. 
• Pick higher fire ratings: Use Class A modules and rated roofs in fire-prone zones. 
• Harden electronics: Shield inverters and combiner boxes from heat and ash; plan spares.
• Wash after smoke events: Schedule cleaning to remove ash and restore output. 
• Use aerosol-aware forecasts: Track smoke, clouds, and dust in day-ahead planning tools. 

Bottom Line

Solar is growing fast, but the skies are changing. Wildfire smoke, tropical systems, and desert dust can trim sunlight and dent production. The effects aren’t the same everywhere. Some places get dimmer, while others get brighter under stable high pressure. Smart design and operations can keep projects producing through the haze. And owners can cut risk with better siting, stronger hardware, and clear O&M plans.

Quick Summary

• U.S. Midwest & Southeast: August saw lower solar output because of wildfire smoke and tropical weather. 
• Canada: Smoke cut “clear-sky” sunlight near fires and lowered irradiance across the East. 
• Europe: Saharan dust knocked solar generation down by up to 20% during June events. 
• South America: Brazil’s winter wildfires surged; smoke reduced sunlight in the south, while the north brightened. 
• Asia: Monsoons and typhoons dimmed India and Southeast Asia; parts of China and Japan brightened under a strong subtropical ridge.