Why winter air feels dry indoors
Cold outdoor air holds little water. When it enters a home through gaps, vents, and door openings and is then heated, its relative humidity drops further. The result is the familiar dry-season pattern: static, chapped skin, and houseplant leaves that crisp at the tips. In summer the reverse can occur, with humid outdoor air raising indoor moisture, especially in basements.
A practical range to watch
Health Canada publishes guidance on indoor relative humidity for residential settings. Rather than memorising a single number, it is more useful to treat humidity as a range you monitor with an inexpensive hygrometer placed away from direct heat sources and exterior walls.
Reading condensation as a signal
Persistent condensation on the inside of windows on a cold morning is a common sign that indoor moisture is high relative to the surface temperature of the glass. It is a useful, low-tech cue to check ventilation and humidifier settings.
How humidity affects houseplants
Many common houseplants originate in more humid environments than a heated Canadian living room. That mismatch shows up as browning leaf edges or slowed growth in deep winter. A few habits reduce the stress without adding equipment.
- Group plants together so transpiration raises the local humidity around them.
- Keep foliage away from radiators, baseboard heaters, and forced-air vents.
- Use a shallow tray of pebbles and water beneath pots, keeping the pot base above the waterline.
Where moisture comes from
Everyday activity adds water to indoor air. Cooking, showering, drying laundry, and even breathing contribute. The balance between these sources and the rate at which air is exchanged determines whether a home trends dry or damp.
| Cooking | Boiling and steaming release moisture; a range hood vented outside helps remove it. |
|---|---|
| Bathing | Showers add moisture quickly; an exhaust fan run during and after use clears it. |
| Drying laundry | Indoor drying racks raise humidity noticeably in smaller rooms. |
| Occupancy | People and plants both add small, steady amounts of moisture. |
Adjusting without overcorrecting
If a home runs dry, a portable humidifier kept clean reduces the worst of the winter dryness. If it runs damp, more ventilation and source control usually help more than a dehumidifier alone. Either way, small adjustments checked against a hygrometer beat large one-time changes.