As the weather changes through the seasons, some of us may notice that these sudden fluctuations sometimes can be asthma triggers. How does that happen, and what can you do to protect yourself?

Hot weather

High temperatures can cause the air around us to become stagnant. As such, pollutants and particles, such as pollen, are trapped closer to the ground. Breathing in these particles triggers asthma symptoms. It is also thought that inhaling hot air causes the airways to constrict, leading to shortness of breath and coughing.

On hot days, plan your activities in the morning or evening, and avoid going outside during the hottest time of the day (between 11am and 3pm). You may keep yourself cool by wearing loose clothing and a hat, staying in the shade, and drinking lots of water. Remember to carry any medication you may need with you, including your reliever inhaler.

Cold weather

When cold air enters your airways, the sudden change in temperature may trigger a spasm that results in asthma symptoms such as wheezing and coughing. Exercising in the cold may thus trigger asthma in a similar manner, since air is breathed in rapidly and does not have the time to warm up before it reaches the airways.

Mould spores in the air may increase in numbers during damp and cold weather, and these can also be triggers for asthma. If you stay indoors more often during the Winter, you may find yourself exposed to indoor air pollutants, including fumes from cooking, dusty furniture, and dust mite droppings. In addition, cold and flu viruses that are common during the Winter could worsen asthma symptoms for some.

Taking precautions during cold weather may therefore involve monitoring weather forecasts regularly, and watching for any warning signs of an asthma attack in relation to potential triggers. If sudden changes in temperatures triggger your asthma, you may choose to wrap a scarf loosely over your nose and mouth before you go out. Doing so will help to warm up the air before you breathe it in. It is also advisable to ensure that you are vaccinated against the flu each year.


During thunderstorms, pollen grains and mould spores may be swept up towards the clouds where it is higher in humidity. The humidity, in combination with winds, cause these particles to rupture and shed much smaller fragments. When fine fragments fall back to the ground, they can be easily inhaled deep into the lungs and trigger asthma attacks. However, such events are not yet fully understood.

Until then, it is advisable to err on the side of caution by trying to stay indoors before, during, and after a thunderstorm. If you have been outdoors, change your clothes and have a shower to wash off any pollen. Be sure to carry your reliever inhaler with you at all times, and make sure to know the signs that your asthma may have been triggered and what to do if it has.

Weather changes can be unpredictable, and it may thus be difficult to pre-empt an asthma attack. It could be helpful to keep a weather diary with you to take note of forecasts, potential asthma triggers in your environment, how your body responds, and what you can do the next time you notice these triggers.

Have you noticed how your asthma responds to changes in the weather? What other steps do you take to manage your symptoms? Share them with us!


American Lung Association. Can a Thunderstorm Trigger an Asthma Attack? 26 July 2017. Electronic. 7 December 2018.

Asthma UK. Weather. 2018. Electronic. 7 December 2018.

British Lung Foundation. Looking after your lungs in hot weather. 2018. Electronic. 7 December 2018.

Heubeck, Elizabeth. The Weather: Wreaking Havoc on Health. 11 August 2009. Electronic. 7 December 2018.

Sample, Ian. Thunderstorm asthma: how seasonal weather can affect human health. 24 November 2016. Electronic. 7 December 2018.

The Lung Association. Heat and humidity. 2016. Electronic. 7 December 2018.