Solar panels are built to shrug off decades of British weather, but "fit and forget" isn't quite the whole story. A little seasonal attention — an hour or two, four times a year — keeps your array producing close to its rated output and helps you catch small problems before they turn into expensive ones.

The good news is that UK homeowners have rain on their side: regular downpours wash away a fair amount of dust and pollen. What rain can't shift is bird droppings, tree sap, moss and the odd bit of gutter debris, all of which can knock your generation noticeably. Here's what to do, season by season.

Spring: clear away winter's leftovers

By March, your panels have spent months being splattered by rain, snowmelt and whatever the wind blew in. Spring is the ideal time to give them a proper once-over.

• Inspect from the ground first. A pair of binoculars or a zoomed-in phone camera will show you bird mess, cracked glass, slipped tiles or a loose bracket without anyone going near the roof.
• Clean only when it's safe. A soft brush, lukewarm water and a long-reach pole from ground level is the safest option. Never use abrasive pads, washing-up liquid or a pressure washer — they can scratch the anti-reflective coating or force water past the seals.
• Watch for new shade. Trees and hedges put on growth quickly in April and May. Even a slim branch casting a shadow across one panel can drag down the output of a whole string.
• Clear the gutters above. Overflowing gutters drop moss and grit straight onto the glass below.
• Check for winter damage. Hail, gales and hard frosts can loosen fixings or crack a panel's backing sheet, so note anything that looks different.

Summer: keep panels cool and clean

Long, bright days mean peak generation, but heat is the quiet enemy. Panel efficiency drops as cell temperature rises, so a roasting panel on a hot July afternoon produces less than the same panel would on a crisp 20°C day.

• Clean early or late. Never hose down hot glass, as the sudden temperature change can cause micro-cracks. Early morning or after sunset is far kinder.
• Keep the inverter breathing. Vents clogged with dust, cobwebs or leaves cause overheating and reduce output. Give the unit a clear, shaded space with room for air to move.
• Don't fight the heat. A small dip in efficiency on very hot days is normal, not a fault.
• Watch for pollen and dust. A dry summer leaves a film on the glass that rain alone won't shift.

Autumn: prepare for the darker months

Autumn is all about protecting your system before the wet, windy weather arrives.

• Clear leaves and debris. Fallen leaves trap moisture against the frame, and damp leaf litter is a perfect home for moss.
• Trim back trees and hedges. Do this while access is easiest, well before the winter gales.
• Check cabling and connectors. Look for rodent damage, cracked insulation or anything loose. Small animals look for shelter in roof voids as temperatures drop.
• Book your annual check early. Installers fill up fast in November, so ring ahead if you want a pre-winter inspection.

Winter: snow, frost and low sun

Short days and a low sun angle mean lower output — that's simply the season, not a fault. Your main job in winter is staying safe.

• Never climb onto a frosty or snowy roof. It isn't worth the risk, and panels are slippery even when dry.
• Don't scrape snow off. Rakes, brooms and improvised poles scratch glass and bend frames. Snow usually slides off on its own, and a light dusting has little effect on generation.
• Check the system after storms. Look for fallen branches, dislodged flashing or new shade that didn't exist last year.
• Keep paths and doorways clear. Sheets of snow sliding off a roof can damage gutters or anything sitting below.

Keep an eye on the numbers all year round

Your system's monitoring app is the single most useful maintenance tool you own.

• Compare this month's generation with the same month last year. A drop of more than about 10% is worth investigating.
• Note any sudden falls — they often point to a tripped isolator, a blown fuse or a failed string.
• Check the inverter display for error codes or warning lights, and jot down anything unusual.
• Keep a simple log of readings and any cleaning you carry out. It's handy for warranty claims and for spotting patterns.

When to call in a professional

Even the most hands-on owner should have the array checked professionally every year or two. An MCS-certified installer will confirm the mountings are tight, test the DC cabling and isolators, check insulation resistance and make sure everything still complies with current standards.

If you spot cracked glass, a burning smell, scorch marks around the isolator, or a sharp unexplained drop in output, switch the system off at the isolator and call a qualified installer straight away. Panels can carry dangerous DC voltage even in dull light, so leave anything beyond a visual check to the professionals.

Look after your array properly and it will quietly repay you — through the short, grey days of winter and the long, bright afternoons of summer alike.