Cold weather
Keeping a patio warm in genuine winter
October is a shoulder-season problem. January is a different one, and several things that work in October stop working when it is actually cold.
In genuine cold, radiant heat and shelter matter far more than raw output, and propane loses vapor pressure as the cylinder cools. Enclose two sides, use infrared aimed at people, and keep the cylinder as full as practical.
What changes when it gets genuinely cold
A patio heater on a 55-degree October evening and the same heater at 25 degrees in January are not doing the same job, and several things shift at once.
- The temperature difference doubles or triples. Heat loss scales with the difference between where you are and where you want to be. At 25 degrees the heater is working against roughly three times the gap it faced in October.
- Convected heat becomes nearly worthless. Warming air on an open patio was always inefficient; in genuine cold with any air movement at all, it is close to pointless. Radiant heat becomes the only part that counts.
- Propane loses vapor pressure. Liquid propane has to boil off to feed the burner, and that gets harder as the cylinder cools — from the weather and from the evaporation itself. A nearly empty cylinder on a cold night can struggle to sustain full output.
- Surfaces are cold. In October the paving and the furniture hold some warmth. In January every surface around you is actively taking heat, including from you.
What still works
Radiant heat, aimed close
Infrared warms people and objects directly, and that transfer does not care how cold the air is. This is why an infrared heater that seems modest in October holds up in January while a convection-heavy setup does not.
The corollary is that distance matters much more. Move the chairs in. Radiant intensity falls off sharply with distance, and in genuine cold the comfortable zone is noticeably tighter than it was in autumn.
Enclosure, which is now doing most of the work
Two sides blocked plus something overhead changes a winter patio more than any heater does. On our sizing model, a covered and sheltered space needs roughly half what an open exposed one does — and that ratio holds regardless of how cold it is outside.
The caution is the same one as always and it matters more in winter, when people are most tempted to close everything in: enclosing a space changes which heater is appropriate. Once air is not moving freely through it, a combustion heater is out and the answer is electric.
The things that are not heaters
- Blankets. Unglamorous, and per dollar the most effective item on any winter patio. Insulation costs nothing to run.
- Something under your feet. Cold conducts up through a slab far faster than through air. An outdoor rug or a mat under the seating makes a real difference and nobody thinks of it.
- Backs to the wind. Seating arranged so people are not facing into the prevailing breeze, with backs against something solid.
- Warm drinks. Trivially obvious, genuinely effective, and it is the reason patios stay occupied in cold countries.
Quick picks
Ranked for fit, not for hype. Output is the maker’s published figure; reach is computed from it or from the maker’s own radius claim, and the table says which. Tap a row for the full write-up, or go straight to the listing.
| # | Product | Best for | Output | Reach | Price |
|---|---|---|---|---|---|
| 1 | Dr. Infrared HeaterNo photo Dr Infrared 1500 WRadiant heat that a breeze cannot blow out, on a plug. 1,500 W is only 5,118 BTU/h, which sounds like nothing next to a propane tower and lands far more of itself on you. | Wind, and anywhere with a roof | 1,500 W | 256 sq ft | Check price on Amazon |
| 2 | Amazon BasicsNo photo Amazon Basics 46kOne of the very few towers whose maker publishes a coverage radius rather than a vague area, and the 9 ft figure survives the arithmetic. That alone puts it ahead of most of the field. | The published-radius honesty test | 46,000 BTU | 254 sq ft claimed | Check price on Amazon |
| 3 | GenericNo photo Clear vinyl curtainsThe highest-leverage purchase on this whole site. Blocking the wind on two sides changes the heat a patio needs by more than any heater upgrade does, and costs a fraction as much. | Turning open sides into walls | n/a | n/a | Check price on Amazon |
Reach marked “claimed” is the maker’s own published figure. Reach without that label is ours, computed from published output at 20 BTU per square foot for an open patio. Neither is a measurement we took.
Top pick · Wind, and anywhere with a roof
Dr Infrared Heater Carbon Infrared Patio Heater, 120 V / 1500 W
Radiant heat that a breeze cannot blow out, on a plug. 1,500 W is only 5,118 BTU/h, which sounds like nothing next to a propane tower and lands far more of itself on you.
- Fuel
- Electric
- Output
- 1,500 W = 5,118 BTU/h
- Reach (computed)
- 256 sq ft · 9.0 ft radius
- Cost per hour
- $0.28
What works
- Infrared warms objects, not air, so it is the only heat that survives a breeze — this is the single reason wind changes the whole buying decision
- No combustion means no flue gas, which is what makes it legal and sensible on a screened porch where propane is not
- Three settings matter more than they sound: 900 W costs a third less to run and is enough most evenings
What does not
- 1,500 W is 1,500 W. Nothing at this wattage heats faster than anything else at this wattage; the differences between electric heaters are beam shape and build, not power
- It heats what it points at. Step out of the beam and you are cold immediately — this is a fundamentally different experience from a tower
- A 120 V plug-in unit is capped by your circuit, not by the maker. See why 1,500 W is the ceiling
| Published specification | |
|---|---|
| Rated power | 1,500 W at 120 V |
| Settings | 900 W / 1,200 W / 1,500 W |
| Element | Carbon infrared lamp |
| Reflector | Mirror aluminum, 90% reflectivity per the maker |
| Housing | Anodized aluminum, rated for outdoor use |
| Mounting | Wall and ceiling brackets plus remote in the box |
| Maker’s coverage claim | None published — the reach figure above is ours |
| Safety listing | ETL listed, per the maker's published product data |
Who it is for
A covered patio, pergola or screened porch where you can mount it overhead and point it at where people sit, and anywhere wind ruins a flame.
What it is not for
A big open patio with nowhere to mount it. Radiant heat needs a line of sight and a place to hang from.
2 · The published-radius honesty test
Amazon Basics 46,000 BTU Outdoor Propane Patio Heater
One of the very few towers whose maker publishes a coverage radius rather than a vague area, and the 9 ft figure survives the arithmetic. That alone puts it ahead of most of the field.
- Fuel
- Propane
- Output
- 46,000 BTU/h
- Reach (claimed)
- 254 sq ft · 9.0 ft radius
- Cost per hour
- $1.35
What works
- A published 9 ft radius is a 254 sq ft circle, and 46,000 BTU is far more than that area needs — a claim on the conservative side of its own specification, which is rare here
- The water-fill base box is a real anti-tip measure, not a sticker: filled, it is the difference between a windy evening and a repair bill
- One-touch ignition and a chain for the cylinder are both small things the cheap clones drop
What does not
- The listing does not name a safety certifying body, only the tilt valve, so we cannot tell you it is CSA listed
- 91 in tall with an open flame: the same wind exposure as every other tower of this shape
- The water box has to be emptied before a freeze or it splits
| Published specification | |
|---|---|
| Rated input | 46,000 BTU/h |
| Published reach | 9 ft radius |
| Dimensions | 32.1" L x 32.1" W x 91.3" H |
| Fuel | 20 lb propane cylinder, not included |
| Safety | Tilt auto-shutoff valve; chain to secure the cylinder |
| Base | Water-fill box for ballast, wheel kit included |
| Maker’s coverage claim | 9.0 ft radius, which is 254 sq ft |
| Safety listing | Tilt auto-shutoff valve; the listing does not name a certifying body |
Who it is for
An open patio where you want the largest honest circle of warmth per dollar and are happy to handle cylinders.
What it is not for
Anywhere enclosed, and anywhere the base cannot be filled with water — an empty ballast box makes this a tall, light, tippy object.
Sources for this entry
3 · Turning open sides into walls
Clear Vinyl Patio Enclosure Curtains, 23 oz, with Grommets
The highest-leverage purchase on this whole site. Blocking the wind on two sides changes the heat a patio needs by more than any heater upgrade does, and costs a fraction as much.
- Fuel
- Accessory
- Output
- Not published
- Reach (computed)
- Not published
- Cost per hour
- n/a
What works
- On our own sizing model, moving a patio from exposed to sheltered cuts the required output by about a third — that is a bigger change than any heater swap
- Clear vinyl keeps the view, which is why people actually leave it up rather than taking it down after a week
- Grommets every 12 inches make it a rope-and-tie job, not a construction project
What does not
- Enclosing a patio changes the heater rules. Once you have walls and a roof, an open-flame propane unit is no longer appropriate — read the safety page before you buy both
- Vinyl goes cloudy and stiff with age and UV, faster in hot climates
- It flogs and cracks in real wind unless it is tied at every grommet, not just the corners
| Published specification | |
|---|---|
| Material | 23 oz clear PVC vinyl tarpaulin |
| Fixing | Metal grommets, ropes and ties included |
| Claimed properties | Waterproof, anti-UV, tear resistant per the listing |
| Intended use | Porch, pergola, gazebo, balcony |
| Maker’s coverage claim | None published — the reach figure above is ours |
| Safety listing | Not applicable — this is a fabric panel, not an appliance |
Who it is for
Any patio where wind is the actual problem and the heater is being blamed for it.
What it is not for
Sealing a space fully. A partly open, well-ventilated enclosure is the goal; an airtight one with a combustion heater inside is dangerous.
Sources for this entry
The propane cold-weather problem, in detail
Worth understanding, because it presents as a heater fault and is not one.
A propane cylinder supplies gas by allowing liquid propane to boil off inside it. Boiling absorbs heat, so the cylinder cools itself as it works — which is why a running cylinder feels cold and sometimes frosts. In cold weather, starting from an already low temperature, the vapor pressure can fall far enough that the cylinder cannot sustain the burner's demand.
It gets worse as the cylinder empties, because there is less liquid to absorb heat from. So the practical winter advice is: keep the cylinder as full as you reasonably can, and if the heater seems to weaken over an evening in genuine cold, that is usually the cylinder rather than the heater. The runtime arithmetic covers the rest.
Never warm a cylinder deliberately. Not with a heat source of any kind. It is a pressure vessel, and the fix is a fuller cylinder or a larger one, not a warmer one.
The setup that actually works in winter
- Something overhead, even partial. A pergola with a canopy, an awning, a porch roof.
- Two sides blocked. Vinyl panels or solid screening on the windward sides, leaving genuine airflow on at least one.
- Electric infrared, mounted, aimed at the seating from seven to nine feet. No flame to blow out, no combustion under a partly enclosed space, and radiant heat that the cold air cannot take away.
- Chairs close together and close to the heat, with backs to the prevailing wind.
- Something under your feet, and blankets within reach.
That setup costs less to run than a propane tower, works in wind, is safe in a partly enclosed space, and needs no cylinder swapped at nine in the evening. It is also, not coincidentally, what most restaurants that keep terraces open through winter actually run.
The honest limit
There is a temperature below which an outdoor space is not going to be comfortable regardless of what you spend, and a fully exposed patio reaches it a lot sooner than a sheltered one. Enclosure moves that line further than any heater does — which is the same conclusion as every other page on this site, arrived at from the cold end.
Common questions
How do I keep my outdoor patio warm in winter?
Cover it if you can, block two sides, and use mounted electric infrared aimed at the seating rather than a heater warming air. In genuine cold, radiant heat and shelter do the work — convected warmth is carried away almost immediately.
What is the best outdoor heater for cold weather?
A mounted electric infrared unit, because radiant transfer is unaffected by cold air or wind and there is no cylinder to lose pressure. If the space is open and large, propane still gives more output, but keep the cylinder full — vapor pressure falls as it cools and empties.
Do patio heaters work in freezing temperatures?
Electric ones do, unaffected. Propane ones work but can weaken, because liquid propane has to boil off to feed the burner and that gets harder as the cylinder cools and empties. Never warm a cylinder deliberately — use a fuller or larger one instead.
Is it cheaper to heat a covered patio in winter?
Substantially. On our sizing model a covered, sheltered space needs roughly half what an open exposed one does, and running cost scales directly with output. Enclosure is the cheapest winter improvement available.
Read next
Keeping the patio usable past October
The four steps in order — shelter, size, position, heat — and why the heater comes last.
Infrared patio heaters, and why wind does not touch them
Four infrared heaters and heat lamps, with what radiant heat does that a flame cannot.
Patio windbreaks, and why they beat a bigger heater
Vinyl, mesh and curtains compared, with what enclosing a patio changes about your heater choice.
Patio heaters for a covered patio
The clearance arithmetic for a roofed patio, and the mounted heaters that actually fit.
How long a propane cylinder actually lasts
The cylinder arithmetic in full: energy content, burn rate, and every size from 15 to 40 lb.