Arizona does have seasons, they just work differently than they do elsewhere. Each one puts a distinct load on a solar array, and knowing which is coming lets you time maintenance instead of reacting to it. Use this as a standing reference for the year.
Spring: Pollen, Wind, and the Start of Nesting
Late February through May brings two things at once. Palo verde blooms coat everything in yellow, and mesquite, olive, and mulberry add their own contributions. Pollen is stickier than mineral dust, so it bonds to glass rather than resting on it, and once a windy afternoon drives desert dust into that sticky layer you get a film that behaves like neither one alone.
Spring is also when birds start looking for nest sites, and the sheltered gap under your panels is prime real estate. What to do now:
- Get the winter and early spring accumulation cleaned off before summer, since your array is heading into its highest-value production stretch.
- Walk the perimeter and check for nesting activity before eggs appear, which keeps proofing simple.
- Note which trees are actually dropping onto your roof. That tells you whether trimming is worth considering.
Summer and Monsoon: Mud, Heat, and Peak Demand
June brings the year's highest sun and the year's highest cooling bills, so this is when lost production costs you the most. Then the monsoon arrives and changes the character of the problem entirely.
Dust storms blanket panels in a heavy layer, and when rain falls through suspended dust it lands as mud rather than washing anything clean. That mud dries into a crust that bonds much harder than loose powder. A storm that looks like free cleaning usually leaves your array worse off than it was that morning.
Practical notes for summer:
- Check your array after any significant dust event rather than assuming the rain handled it.
- Schedule cleanings for early morning. Spraying water on glass that has been in full sun all afternoon is hard on panels and dangerous for anyone on the roof.
- Remember that panels already give up some efficiency to heat in an Arizona summer. Soiling is the part of that loss you can remove.
Fall: The Best Production Window of the Year
Once the monsoon ends, the Valley settles into clear skies and mild temperatures, which is the most favorable combination your panels will see all year. Cooler air means they run more efficiently, and there is very little cloud cover to work around.
The catch is that fall follows the dirtiest months. Monsoon residue, dried mud, and settled dust are all sitting on the glass just as conditions turn ideal. A cleaning in October is probably the single highest-value visit on the calendar, because it clears months of accumulation right as the array enters its strongest stretch. This is also the practical time for a full inspection, since a comfortable roof makes for a thorough one.
Winter: Low Sun and Warm Spots Under Panels
Winter is quiet for dust and busy for wildlife. The gap under a solar array holds warmth overnight, which makes it attractive to birds and the occasional rodent looking to get out of the cold. Nesting picks up earlier here than most people expect, often by late January.
Winter priorities:
- Install bird proofing now if you have been putting it off. Nests are least likely to be active, which keeps the job to a straightforward barrier installation.
- Watch for new shading. The low winter sun angle throws longer shadows, so a wall, chimney, or grown tree can shade panels in December that it never touched in June.
- Take advantage of the shorter days. Less production means a cleaning visit costs you less downtime.
- Set your schedule for the coming year rather than waiting for a problem to prompt it.
Two Bits Solar Cleaning works on this rhythm year round across the Valley, cleaning with deionized water so nothing is left on the glass and fitting bird proofing during the quieter months. If you would rather have your visits on the calendar than on your mind, let us set up a schedule that matches your roof.