Coping with rain is part of successful tent camping.
In order to help novice family tent campers easily prepare for various warm and cool weather precipitation, this simple, common rain scale works best.
This scale is easy for both English and Metric system campers to remember and apply; each threshold increases by a factor of ten.
Tent campers can consult local weather forecasts to determine how much rainfall to expect during their camping trip.
U.S. tent campers can get a local weather forecast from the website www.weather.gov. Click once on the proper state and again on the location of the campground within the state. You will be taken to a detailed, 7-day forecast of the region.
If there are any links to special weather bulletins at the top of the 7-day forecast, be sure to click on the link and read the bulletin. The bulletins will last for the current storm cycle and will then be taken down.
Campetent offers a Waterproof Coating vs Rainfall Chart further down the page to assist family tent campers in understanding how waterproof coatings stand up to rainfall.
Tent Camping Rain Chart
0 inches per hour (0 mm per hour): No Rain
(Fair weather or overcast)
Fair weather is obviously the most comfortable weather for tent camping and being outdoors.
Campers do not need to be concerned about bringing special clothing, shelters or tarps for wet weather.
Weather agencies do an excellent job of forecasting fair weather for a region, so tent campers can feel confident about planning a camping trip in this weather.
As long as the wind is light, most any tent is suitable for this weather.
In fair weather, a tent will be used mainly for privacy and against insects, as there will be little or no weather to shelter from.
Fair weather occurs over much of the US approximately 50 to 60% of warm-weather days.
0.001 to 0.005 inches per hour (0.025 to 0.125 mm per hour): Drizzle or Sprinkle Shower
These intensities are too light to be caused by raindrops and may well not appear in a weather forecast.
Fog is not precipitation but is included in this category to aid campers in preparing for damp weather.
It occurs when cool moist air gets trapped under warm air.
Fog floats in air and does not fall onto the ground.
It is quite common along the coasts.
It usually occurs overnight, lasts into the early morning and lifts as the sun rises higher in the sky.
Fog can make a tent clammy inside.
It will wet tent fabric a bit, but there won’t be any noticeable transfer onto sleeping gear.
Water absorbing camping gear should either be sprayed with a water repellent treatment or stored away from fog.
Drizzle is precipitation. However, the droplets are too tiny to be considered raindrops.
It can float somewhat on air currents, but eventually falls onto the ground.
Drizzle can last long enough to wet out older tent fabrics with a light waterproof coating. However, it won’t seep through enough to puddle on the floor.
Spraying the fabric of these tents with a water repellent treatment can improve the tent’s performance in drizzle and light rain.
A sprinkle shower is very light rain that does not completely wet where it falls.
It usually also lasts a brief time and either develops into light rain or passes over.
A sprinkle shower is the easiest form of precipitation for campers to cope with. It can often be largely ignored.
Even if window flaps are not closed, there is usually little dampness inside the tent, which can later easily evaporate. Screen rooms can be left open.
Weather forecasts and extremely light precipitation
Fog and drizzle can greatly affect visibility around the campsite and on the road.
Drizzle is more common in cool temperatures than in warm.
In Summer, drizzle is more difficult to forecast than rain. During Summer in the U.S., drizzle is more common along the coasts and in the mountains than in other regions.
Weather radar may have a difficult time detecting it. The rate and accumulation of drizzle is generally not recorded.
Weather forecasting agencies may ignore light drizzle, as it has little impact on driving or on people living indoors.
Since tent campers spend all of their time outdoors, these extremely light forms of precipitation affect them more than most. Campers may find that weather forecasting agencies do not provide much advance information about this category of precipitation.
Rates above 0.005″ (5 thousandths of an inch) per hour are generally caused by very light rainfall and any accumulation is referred to as a “trace.” These scattered raindrops will not completely wet the fabric or surface where they fall.
0.01 to 0.05 inches per hour (0.25 to 1.25 mm per hour): Very Light to Light Rain.
Very light to light rainfall and hourly rainfall readings in the low hundredths of an inch are quite common in Summer throughout the U.S.
These rains will have minimal effect on camping gear and campsites.
Most any sealed tent with minimal waterproof coating on the fabric can repel very light rain.
Light rain gear and possibly a tarp or canopy will be enough extra gear to camp in this weather.
A tarp can be rigged either to provide a sheltered space for sitting in front of the tent or for cooking and eating away from the tent.
Campers should be able to move about in this precipitation without worrying about their clothing being quickly wetted.
Novice campers should consider limiting their first few camping trips to fair weather and light precipitation, in order to learn basic camping skills without worrying about preparing for wetter weather.
0.1 to 0.5 inches per hour (2.5 to 12.5 mm per hour): Moderate to Heavy Rain.
(May include small hail)
Rain intensities in tenths of an inch per hour refers to weather which family campers associate with a rainy day.
Tent campers will need to prepare for this precipitation, which can quickly wet clothing and other camping gear.
Rain gear and rain footwear are necessary. A rain poncho, long raincoat or a complete rain suit is very useful for tent campers who will be out in the weather for more than a short time. An umbrella helps to keep rain off of your head and thus from getting inside your raingear through the hood or collar.
A tent with hooded windows and a hooded vent offers ventilation and a view in the rain.
A tent with a covered doorway allows campers to enter through the tent door without rain getting into the tent.
A tarp or stand-alone canopy can be set up to offer a separate, sheltered space outside of the tent body.
Campground staff can also assist tent campers in choosing a good tent campsite which will fare well in the rain.
As these rains increase, tent pads greatly reduce the risk of flooding around the tent.
Most tent leakage comes through poorly sealed seams.
Once it begins raining, campers will not be able to seal tent seams until the rain has passed and the fabric has dried.
Be sure to seal any unsealed, exposed seams before camping in the rain.
Even an inexpensive tent can be modified to get through moderate to heavy rains. Here are a few tips for campers in this situation:
Fortunately, there is an easy emergency fix for a tent that is leaking in the rain: Lay a polyethylene tarp over the tent and secure the tarp with ground stakes or rocks. This will stop the leak. Then mop up any leakage inside the tent with a towel.
The tarp needs to allow air to pass underneath on two sides to ventilate the tent and provide oxygen to campers inside.
The tarp should be only marginally larger than the tent body. If the tarp is much larger than the tent, campers will have to fold an edge or two to reduce the size and secure the tarp to the ground.
The tarp should also be able to protect the doorway from rain, allowing people to more easily enter and leave the tent.
Leaky tent floor
There is also an easy emergency fix for water coming through the tent floor: Lay a large single sheet of plastic sheeting on the floor inside the tent and place all camping gear on the plastic sheeting. This sheet-plastic floor liner needs to extend an inch or two up the walls on all sides, so that any leaking water stays under the plastic.
Plastic sheeting is available in rolls from any hardware store.
As long as you have not pitched the tent in a depression, the plastic sheeting should protect your camping gear from any moisture that passes through the floor fabric. Use a tarp instead, if you need to, but sheet plastic works better for this situation.
If these rains are due to a thunderstorm, tent campers should consider taking precautions against lightning: once you hear thunder, head for shelter in a vehicle or in an enclosed campground building, such as an office or a shower/toilet block.
Tents do not offer protection from lightning.
Weather forecasting agencies cannot predict rain for any specific, small area.
They predict how much of their forecast region will experience rain.
It’s not possible to predict the specific areas in a forecast region that will experience rainfall.
2-season family camping tents should be able to resist rain falling at 0.1 inches per hour.
However, as moderate rains increase, single-wall family tents with lighter waterproof coatings may begin to experience damp walls and potentially some moisture seeping through the fabric and running down the inside of the tent wall onto the floor, creating a puddle.
Wick through vs seep through
Wick through occurs when bedding or clothing touch wet tent fabric, draw moisture and become wetted.
This is a fairly common occurrence with tents with poor rain resistance.
As long as moisture wicking gear is kept away from the tent walls, the inside of the tent will remain fairly dry.
Seep through is more serious and occurs on its own without wicking. Rain is driven through soaked fabric, runs down the inside of the tent and pools on the floor.
This is a less common issue and occurs when tents with poor rain resistance stand in heavy rain for long periods of time.
Make sure that the water-repellent finish on the outside of the tent fabric is in good working order. Raindrops should bead up and roll off the fabric. If the original water-repellent treatment has worn off, apply a new spray treatment.
A quality tent means little to no preparation for rain, other than closing the window and door storm flaps—and it also means no surprises.
Remember to bring an emergency tarp to cover an inexpensive tent, if necessary.
Drivers may need to reduce speeds by up to 10 mph or more as the rain rate increases from light to heavy through this range.
1 to 5 inches per hour (25 to 125 mm per hour): Very Heavy to Extreme Rain.
(May include large hail)
Rain intensities in multiples of an inch per hour refers to very heavy to torrential rains.
Very heavy rains bring the risk of flash floods to campgrounds, so 1 inch per hour steady rainfall is a prudent, upper limit for seasoned, family tent camping with a quality tent.
National Weather Service flood guidance states that there is a risk of flash flooding when 2 to 3 inches of rainfall accumulate in as many hours. (In metric – 50 to 75 mm of rain in 2 to 3 hours.) The NWS will issue flash-flood watches and warnings, so campers shouldn’t have to determine whether flooding is possible.
1 inch per hour rainfall is a threshold where family tent campers in much of the U.S. will need to make a decision as whether to ride out a short, heavy rain shower, or, if the forecasted rains are expected to last longer, to break camp and leave the area before the rains come.
If rains increase beyond this rate for more than a brief shower (“It’s raining cats and dogs,”) things can quickly get out of control in a campground.
If the area floods, campers may need to break camp, sometimes in the middle of the night. Country roads in low-lying, rural areas can easily become impassible. Driving home along possibly flooded roads is quite dangerous, especially at night.
Wind and hail
Strong winds can also accompany these rains, and tent campers in exposed campsites will need to determine whether their tent can hold up to the wind. Campers in sheltered, forested sites will need to determine whether the trees around the tent can hold up to the wind and rain without being toppled.
Small, quarter-inch (pea-size) hail is possible in this weather. A tent can protect against small hail, as long as the hail cannot accumulate in any sags in the fabric.
A tent with a full rainfly and vestibule generally offers better shelter in these rains. However, ventilation and view may be limited for family tents with a full fly.
Be careful when camping near rivers in these rains. If flash flooding occurs, runoff will flow into the river, possibly causing it to overflow its banks.
Tent campers in semi arid, western U.S. states need to be more aware of moderate and heavy rainfall, because of the hard soil, which quickly saturates and causes rainwater to pool, run and flood.
Drivers will want to be off roads in this rain. There will be no visibility beyond the windshield.
Rainfall vs Waterproof Coating
Campers will also likely want guidance as to how much rainfall they can expect their tents to withstand.
Campetent has devised a chart to help tent campers get an idea of how much rainfall various tent fabrics might comfortably resist.
Both the intensity and length of time of rainfall determine whether tent fabric will wet out or possibly allow rain to seep through.
Long periods of rain in excess of these rates may result in overly damp walls or possibly in some water running down the inside of the tent wall and pooling on the floor.
Tent-Fabric Waterproof Coating vs
Rainfall Rate Chart
|Tent Fabric Waterproof Coating Rating (HH)
|Tent Season Rating
|Approximate Maximum Rainfall Rate
|0.1″ per hr
|Light vertical rain
|Moderate vertical rain
|0.25″ per hr
|Moderate vertical rain
|Moderate vertical rain
|0.5″ per hr
|Heavy vertical rain
|1.0″ per hr
|Heavy vertical rain
|1.0″ per hr
|Heavy wind-driven rain
The waterproof coating rating applies only to the fabric, not to the seams. However, well sealed seams can be more rainproof than the tent fabric, mainly because the seam sealer is thicker than the fabric coating.
A family tent that does not list a waterproof-coating rating should be assumed to be a 2-season tent.
Because the chart addresses the intensity, but not the time length of rainfall, campers will need to use their own judgement when rain is forecast.
The takeaway from this chart is that, when shopping for a tent, campers need to think about how much rain they expect to camp in.
Campers who already have a tent should think about the rain resistance of the fabric before choosing to camp in rainy weather.
Methodology for chart
For readers who are interested, the above chart was devised by comparing the resistance of various waterproof coatings in psi to the “falling force” (dynamic pressure) of various rainfall rates in psi and applying a conservative adjustment for a few factors which are difficult or impossible to measure.
Beyond 1-inch-per-hour rainfall, the “falling force” of rainfall does not increase substantially, because raindrops break up after reaching a certain size, limiting the force they apply to tent fabric. This force is what can cause water to pass through the fabric and coating.
This chart is offered only as a rough guide for understanding how waterproof coatings stand up to rain.