Sustainable living in summer

The most sustainable summer is one where you spend as much time as possible outside, eat what's actually in season, and work with the heat rather than throwing energy at it. Most of the practical changes here save money too.

Staying cool without (or with less) AC

Air conditioning is one of the most energy-hungry things in a home, and as summers become more intense in many parts of the world, the temptation to run it constantly grows. The good news is that a set of passive cooling techniques — used well — can keep most homes comfortable for most of a hot summer, with AC as a last resort rather than a reflex. For a comprehensive look, see our guide to staying cool without AC.

• Block heat before it enters. Close blinds, curtains or shutters on windows that face the sun during the hottest part of the day — particularly those facing west in the afternoon. External shutters or blinds are more effective than internal ones because they stop heat entering the glass in the first place.
• Use the cool hours. Open windows wide in the early morning and late evening when outside air is genuinely cooler than inside. Close everything up before the day heats up. In many climates this cross-ventilation is enough to make nights comfortable.
• Fans move air, not heat. A ceiling fan or a good standing fan costs a fraction of what AC does to run and makes a room feel significantly cooler by increasing air movement over your skin. Position box fans to draw hot air out of one window while pulling cooler air in from another.
• Cool yourself, not the room. A cool damp cloth on your neck, a cool shower, cold water to drink and loose, light-coloured clothing made of natural fibres (linen, cotton) lower your body temperature directly. This is more efficient than trying to cool an entire space.
• Avoid heat sources inside. Ovens, tumble dryers and dishwashers running during the hottest part of the day heat your home from inside. Use them in the morning or evening, cook outside or use a microwave, and air-dry laundry outside.
• If you do use AC, use it well. Set it a couple of degrees warmer than you think you need — your body adjusts. Keep the room sealed, service the unit so it runs efficiently, and turn it off when you go out.

Water-wise: heat, garden and home

Summer is when water use peaks and when water is often scarce. In many regions, summer heat is accompanied by drought restrictions. Whether or not there are official limits where you live, using water thoughtfully in hot months is a practical and responsible habit. Our garden calendar has more detail on seasonal watering strategies.

• Water the garden in the early morning or evening. Watering during the heat of the day means a large proportion evaporates before it reaches the roots. Morning is ideal — soil stays moist through the day and leaves dry before evening, reducing the risk of fungal issues.
• Collect rainwater. A rain barrel or water butt connected to a downpipe collects enough water during wetter periods to supply a kitchen garden through dry spells. Even in dry summers, a single rainy day can fill a butt.
• Mulch generously. A layer of mulch (compost, bark, straw or even cardboard) around plants dramatically slows evaporation from the soil surface. A well-mulched bed needs far less watering than a bare one.
• Water the roots, not the leaves. A watering can directed at the soil at the base of a plant is far more effective than a sprinkler wetting the leaves. Drip irrigation or a soaker hose delivers water exactly where it's needed.
• Indoors, hot weather can increase water use. Extra showers, filling paddling pools, hand-washing more frequently — these add up. Take shorter showers, reuse paddling pool water on the garden, and fix any dripping taps promptly.

Seasonal eating, picnics and BBQs

Summer is arguably the most rewarding season to eat locally and seasonally — tomatoes, courgettes, cucumbers, peppers, aubergines, corn, stone fruits, berries and salads are all at their peak and genuinely inexpensive when bought in season. The contrast with the same produce out of season (grown under glass with artificial heat and light, or flown in) is enormous both in taste and footprint. For food waste reduction tips, see our guide to cutting food waste.

• Cook outside when you can. Using a BBQ or outdoor gas burner keeps heat out of the kitchen and makes eating outside enjoyable. Even a simple camping stove on a balcony saves the house from heating up.
• Low-waste BBQ basics. Use real plates, real cutlery and real glasses rather than disposable ones — they're easier to use and generate no waste. Plan quantities based on who's actually coming, not a theoretical maximum. Use marinades, rubs and sauces to use up vegetables alongside or instead of meat.
• Choose charcoal thoughtfully. If you use a charcoal BBQ, lumpwood charcoal (often made from offcuts and sustainably sourced wood) is generally preferable to briquettes made with binders and fillers. Better still, a gas or electric grill if you cook outdoors frequently.
• Pack picnics with reusables. A small kit of a few containers, a cloth, a reusable bottle and some proper cutlery weighs almost nothing and avoids a pile of single-use plastic film, bags and packaging. Beeswax wraps or reusable sandwich bags work well for packed food.
• Preserve the glut. When produce is abundantly in season — stone fruits, berries, tomatoes, cucumbers — it's often available cheaply in bulk. Jamming, pickling, freezing or drying these at their peak means you enjoy local food long after summer ends.
• Keep food cold and safe. In hot weather, food left out spoils quickly. Use a cool bag with ice packs for picnics and BBQs, and don't leave perishable food out for more than two hours in the heat. Food safety in summer means wasting less, not more.

Summer travel and staycations

Travel is one of the most significant discretionary sources of emissions for many people, and summer is peak travel season. There's no single right answer here — travel has genuine value and it's not the purpose of this guide to tell you not to go anywhere. But there are real choices that make a difference.

• Land travel is dramatically lower-impact than flying. For journeys that can be made by train, coach or ferry, the difference in emissions compared to flying is substantial — often a factor of ten or more. Many train journeys in the same time as a flight (including airport time) are competitive and considerably more enjoyable.
• A staycation done well is not a compromise. Exploring your own region with the same curiosity you'd bring to an abroad trip — independent accommodation, local food, trails and heritage — is often cheaper and just as rewarding. You also skip the exhaustion of long-haul travel.
• If you fly, fly less far and less often. Non-stop flights produce fewer emissions than those with connections. Economy class has a lower per-passenger footprint than business class (more passengers per aircraft). If a trip is genuinely important to you, staying longer makes the journey's footprint more worthwhile.
• Travel light. Lighter bags mean less fuel used, and they make slow travel — using trains, buses and walking — much more practical and enjoyable.
• Holiday accommodation matters. Smaller, locally owned accommodation has a lower footprint than large resort hotels with pools, intensive air conditioning and food flown in. Staying in self-catering accommodation where you can cook some meals also cuts both cost and waste.

Sun care and reusables on the go

Summer life means spending more time away from home — at the beach, in parks, at outdoor events — which tends to generate more on-the-go waste. A small amount of preparation makes a big difference.

• A reusable bottle is the single most useful summer item. Staying hydrated in heat is important, and buying single-use plastic water bottles is expensive and wasteful when safe tap water is available. Most cafes, libraries, public fountains and refill apps will top up a reusable bottle for free.
• Choose reef-safe sun protection. Some chemical sunscreen ingredients (particularly oxybenzone and octinoxate) are damaging to coral and marine life. Mineral sunscreens based on zinc oxide or titanium dioxide are widely available, effective and less problematic in aquatic environments.
• Bring your own snacks and containers. Outdoor events and tourist areas are where single-use packaging is most prevalent and expensive. A few reusable containers with food from home or a market stall save money and waste.
• Leave outdoor spaces as you found them. Carry a small bag for rubbish when you visit parks, beaches and trails. Take everything you brought — and a little extra if you can. Natural spaces clean themselves better when they're not covered in litter.

Managing waste in the heat

Hot weather accelerates food spoilage, increases composting activity and — in some regions — changes how waste is collected or managed. A few adjustments keep things under control.

• Compost bins heat up faster. A hot summer compost bin can work extremely quickly, but can also dry out and become inactive, or attract pests. Keep outdoor compost bins covered, add dry brown material (cardboard, dried leaves) with every food addition, and water it occasionally if it dries out completely.
• Refrigerate more in hot weather. Fruit, bread and even some vegetables that are fine at room temperature in winter can spoil within a day or two in summer heat. Use the fridge more generously in hot weather to reduce waste — it's more energy-efficient to run it at a set temperature than to keep throwing out food.
• Reduce the frequency of cooked food preparation. If you're cooking for a household, hot-weather cooking that produces too much food is a waste problem because leftovers go off faster. Smaller, more frequent cooking or cold meals (salads, grain bowls, cold cuts) reduce this risk and are more appropriate to hot weather anyway.

Your summer sustainability checklist

• Close south- and west-facing blinds during peak heat; open windows early morning and late evening.
• Set up a rain barrel or water butt before the dry season.
• Mulch garden beds to retain moisture and reduce watering.
• Pack a reusable bottle, container and cutlery for every day out.
• Plan BBQ or picnic quantities realistically to minimise food waste.
• Buy stone fruits or berries in bulk when they're cheapest and freeze or preserve them.
• Research a local or land-travel destination before booking a flight.
• Switch to a mineral sunscreen for beach and swimming trips.