Does Air Quality Get Worse At Night? 5 Summer Sleep Solutions For Better Rest
Better sleep starts tonight. Read on to learn how.
You close your bedroom door, turn off the lights, and settle in for the night. But while you're counting sheep, something unexpected is happening to your air quality. Recent studies from NYC's air monitoring networks found that nighttime air quality averaged 34 AQI compared to 25 during the day, with the highest pollution spikes occurring around 11:30 PM.
If you've been waking up with a stuffy nose, dry throat, or feeling less rested than you should, poor nighttime air quality might be the culprit. And with summer temperatures climbing (2025 is virtually certain to rank in the top-five warmest years on record), the challenge of maintaining healthy bedroom air becomes even more critical.
Why Your Bedroom Air Quality Drops After Dark
Several factors converge to create poorer air quality at night.
- Limited Ventilation: Most of us sleep with our doors and windows closed. But without proper air circulation, carbon dioxide levels can rise to 2,500-3,000 parts per million, three times the recommended levels. A Technical University of Denmark study found that college students with increased overnight fresh air had both improved sleep quality and better next-day performance.
- Temperature Inversions: At night, cool air gets trapped near the ground by warmer air above, creating a lid that traps pollutants. This natural phenomenon means outdoor pollution often peaks during sleeping hours, contradicting the common belief that nighttime air is cleaner.
- Sorry, Your Mattress Is Working Against You: According to the 2015 "Dusty Dozing" study, movement and body heat during sleep cause mattresses, bedding, and pillows to emit air pollutants. The longer you're in close contact with these materials, the more volatile organic compounds (VOCs) you're exposed to.
The Summer Sleep Challenge
Summer adds extra complications to nighttime air quality:
- Rising Temperatures: When nighttime temperatures rise just 1°C above normal, people are significantly more likely to experience poor sleep
- Increased Ozone: Summer heat drives ground-level ozone formation, which peaks during afternoon but lingers into evening
- AC Dilemmas: While air conditioning helps, research shows that direct airflow (even at low velocities) increases body movements and heart rate during sleep
5 Science-Backed Solutions for Better Summer Sleep
1. Strategic Air Purification
Position an air purifier in your bedroom to run continuously overnight. Models like the Airmega 100 operate at whisper-quiet 20 dB—softer than a library. The key is choosing a unit sized for your room that won't disturb your sleep while removing pollutants.
2. Smart Temperature Control
The optimal sleeping temperature is 16-18°C (60-65°F). Use these strategies:
- Run your AC earlier in the evening to pre-cool the room
- Set it to maintain temperature without direct airflow on your body
- Consider a programmable thermostat to gradually increase temperature toward morning
3. Ventilation Without Compromise
If outdoor air quality permits:
- Crack a window on the opposite side of prevailing winds
- Use a window fan on exhaust mode to pull stale air out
- Install door vents to allow air circulation even with doors closed
4. Choose Your Bedding Wisely
Your summer bedding materials matter. Here are some of our favorite options:
- Natural fibers like cotton, linen, or lyocell that breathe better
- Low-VOC or certified organic mattresses and pillows
An extra tip: Always air out new bedding thoroughly before use to reduce chemical off-gassing!
5. Monitor and Adjust
Knowledge is power when it comes to air quality. Using an air quality monitor to track CO2, temperature, and humidity levels gives you real-time insight into your bedroom environment. Set alerts to notify you when any of these metrics exceed healthy ranges, so you can take action before your sleep suffers.
Consider keeping a sleep journal alongside your air quality data—you might discover patterns like sleeping better on nights when CO2 stays below 1,000 ppm or when humidity hovers around 40-50%.
Custom Solutions for Your Specific Needs
Different sleepers face different challenges. If you're dealing with:
- Allergies: Consider the Custom Allergen Filter (compatible with Mighty AP-1512HH & 200M) for ultra-fine particle capture targeting pollen and dust mites
- Pet Dander: The Custom Pet Filter offers enhanced dander capture plus specialized odor control
- Wildfire Smoke: The new Airmega 350 & 450 models are compatible with the 3-in-1 Intense Smoke+ filter specifically designed for heavy smoke conditions
Creating Your Sleep Sanctuary
Research shows that those living in high-pollution areas are 60% more likely to suffer from poor sleep. But you don't have to accept poor air quality as inevitable. By understanding why bedroom air quality deteriorates at night and implementing targeted solutions, you can transform your sleeping environment.
The goal isn't perfection—it's progress. Start with one or two changes and monitor how your sleep improves. Your body (and your morning self) will thank you.
Ready to breathe easier tonight? Explore Coway's range of bedroom-friendly air purifiers designed for quiet, effective overnight operation.
Disclaimers
1Coway air purifiers have been proven to trap dust, pollen, dander, viruses and bacteria in the air based on KCL (Korea Conformity Laboratories) testing.They have been tested in a 30㎥ size chamber according to the Korea Air Cleaning Association standard (SPS-KACA 002-132:2022 Modified) to measure the 0.01㎛ size of particle removal rate. It was tested on maximum airflow speed in normal room temperature and humidity conditions. The performance may vary in the actual living environment of customers.
→ Tested with Airmega Aim, 50, 100, 150, 160, Tower AP-1216L, Mighty AP-1512HH, MightyS AP-1512HHS, 200M, Icon, IconS, 230, 240, 250, 250 Art, 250S, 300, 300S, 350, 400, 400S, 450, ProX
299.97% of viruses, bacteria, fungi and pollen were verified to be removed from the air for Coway air purifiers which have Green True HEPA™ filter applied based on the Japan Food Research Laboratories(JFRL) testing according to JEM 1467 standard.
→ Tested with Coway Airmega Mighty AP-1512HH, MightyS AP-1512HHS, 250, 250 Art, 250S, 300, 300S, 400, 400S
→ All tested by JFRL and received above result within below time.
All tested by JFRL and received above result within below time.
- Virus: Tested with Escherichia coli phage ΦX174 NBRC 103405, 60 minutes
- Bacteria: Tested with Staphylococcus epidermidis NBRC 12993, 60 minutes
- Fungi/Mold: Tested with Penicillium citrinum NBRC 6352, 60 minutes
- Pollen: Tested with Cedar Pollen extract, 60 minutes
3Aerosol test conducted in a Biosafety level 3 laboratory with two Coway air purifier models, Coway Airmega 250 and 400 for removal of SARS-CoV-2 Aerosol by US based MRI Global, a not-for-profit laboratory and partner of US Department of Defense. The test was conducted in a 13.1ft3 chamber. Virus was aerosolized for 15 minutes and the product was turned on high for 2 minutes. Result showed each product effectively removed over 99.98% of the SARS-CoV-2 in 2 minutes. This is a result from a laboratory experiment condition and result may vary in different conditions. This result does not imply it kills SARS-CoV-2 or prevents the transmission of Covid-19. Coway Airmega 250S and 400S are identical to the tested models and has equal performance with an additional mobile connectivity function.
4The concentration of ammonia, acetaldehyde and acetic acid were proven to be removed within 30 minutes by FCG Research Institute, Inc. Human Life Science Lab. It is not a demonstration result in the actual use space. Not all odors and gases may be supported. → Tested with Coway Airmega 150, 160, Mighty AP-1512HH, MightyS AP-1512HHS, 400, 400S
5The coverage area of the air purifier is based on an area where the air cleaner can make two air changes per hour (ACPH). An air change per hour translates to how many times an air purifier can clean an area, assuming the height of a ceiling to be 8 ft, in one hour. Therefore ** means two air changes per hour means that the cleaner can clean the area once every 30 minutes and * means air changes per hour means that the air purifier can clean the area once every 60 minutes.
10Terms and conditions apply. Discounts, including promotions, coupons, bundle discount and subscription discount, cannot be stacked on top of other coupons. During promotional periods, discount codes will not be able to be applied to orders. Promo codes may apply to products only—filters, accessories, and new products within 3 months of the release date are not included.
