Rehearsal is on, the carolling date is set, and the haze readings have crept up. Should you sing outdoors?
This guide helps you decide as a singer, with official advice as the starting point. It isn’t medical advice.
Start with the official advice
The Ministry of Health (MOH) says a PSI reading of 101 or above is deemed unhealthy. It also says the health impact of haze depends on your health status, the PSI level, and the duration and intensity of outdoor activity [1]. The National Environment Agency (NEA) publishes daily updates. It suggests using the 1-hour PM2.5 readings for outdoor activities you’re about to do, and the 24-hour PSI forecast for planning the next day [2]. [Add links to MOH’s haze page and NEA’s live haze updates.]
Who needs extra care
MOH says children, the elderly and people with chronic lung or heart disease are more sensitive to the health effects of haze, and it advises pregnant women to reduce their exposure [3]. If that includes you, or anyone in your group, plan more cautiously, and ask your doctor what’s right for you.
Think about how long you’ll be out
An hour of standing, singing and carrying equipment is different from ten minutes. MOH lists the duration and intensity of outdoor activity as one of the factors that matter [1], so the length of the rehearsal or carolling session counts as much as the reading.
Questions to ask your choir leader
- Can rehearsal move indoors, or can we sing in shorter blocks with breaks?
- Is there a plan B for the carolling?
- Can anyone sit out without pressure?
- Can we use a microphone, so no one has to push?
If you carry on outdoors
- Keep sets short, with breaks.
- Sip water.
- Avoid shouting between songs.
- Stop if you feel unwell. MOH advises consulting a doctor if you develop breathing difficulties [3].
Your voice and throat
MOH notes that haze can irritate the eyes, nose and throat, even in healthy people [1][3]. If your throat feels dry or scratchy, MOH says drinking plenty of water may help symptoms such as a dry or itchy throat [3]. Symptoms can take up to three days to appear after exposure [3], so notice how you feel over the next few days.
When to see a doctor
MOH advises consulting a doctor if you develop breathing difficulties [3]. Clinics also advise seeing a doctor for wheezing, chest tightness, worsening asthma, or a cough or sore throat that persists or worsens [4][5]. The National Institute on Deafness and Other Communication Disorders (NIDCD) advises seeing a doctor if your voice has been hoarse for more than three weeks, especially without a cold or flu, or if you have pain when speaking or swallowing [6]. We’d add one thing of our own: please don’t sing through it until you’ve been checked. Vocalogy provides voice training and coaching, and we don’t diagnose or treat medical problems.
The bottom line
Singing together is one of the joys of the festive season, and it will still be there when the air clears. On a hazy day, the best plan starts before anyone opens their mouth. Check the official readings, consider who in your group needs extra care and how long you’ll be outdoors, and agree on a plan B with your leader.
If the readings are poor, moving indoors, shortening the set or sitting this one out are all reasonable choices. Every singer should be able to make an informed choice about taking part, and every leader can make that choice easy. If you’re unsure, ask your doctor, and save the carols for a day when the air is better.
Related reading
If you’re planning a whole event, see Haze and Your Performance: Postpone, Move Indoors or Go On?
Where to start
Want to prepare for your carolling indoors? Explore 1:1 coaching or ask us on WhatsApp.
References
- Ministry of Health, Singapore. Haze. https://www.moh.gov.sg/others/haze/
- National Environment Agency. Haze Situation Update (4 October 2026). https://www.nea.gov.sg/media/news/advisories/index/haze-situation-update-4-october-2026
- Ministry of Health, Singapore. FAQ: Impact of Haze on Health. https://www.moh.gov.sg/newsroom/faq-impact-of-haze-on-health/
- Doctor Plus. Haze in Singapore: How to Protect Your Health and When to See a Doctor. https://drplus.com.sg/articles/haze-in-singapore-how-to-protect-your-health-and-when-to-see-a-doctor/
- Parkway Shenton. How the Haze Can Affect Your Health. https://www.parkwayshenton.com.sg/health-plus/article/singapore-haze-health
- National Institute on Deafness and Other Communication Disorders. Hoarseness (fact sheet, updated October 2011). https://www.nidcd.nih.gov/sites/default/files/Documents/health/voice/NIDCD-Hoarseness.pdf