Thin fog that drifts away in five minutes ruins a good haunted yard. The fix is usually water temperature and bucket count. Buying more dry ice for Halloween fog than you need will not thicken it. Here is the math, worked out for one bucket, two buckets, and a few hours of trick-or-treaters.
Skip ahead if you just want the number: for one bucket running nonstop, figure 12-18 lb for an hour, 24-36 lb for two hours, 36-54 lb for three hours. Two buckets double whatever you land on.
How much dry ice do I need for Halloween fog?
The rule of thumb is 2-3 lb per 10 minutes per bucket of hot water. Running one bucket nonstop for an hour takes 12-18 lb, two hours takes 24-36 lb, three hours takes 36-54 lb. Running the fog machine in bursts, only when groups of trick-or-treaters show up, uses a lot less than running it nonstop for the whole evening.
Most front yards don't need three hours of continuous fog. Trick-or-treaters tend to come in waves: a rush right after dark, then quieter stretches. If you only trigger the bucket when kids walk up the path, a 15 lb bag can carry you through an entire evening instead of one hour.
Hot water or warm water, and why it matters more than the ice
The hotter the water, the more fog you get. As the water cools, the fog thins out, even with ice still in the bucket. Water temperature decides how your fog looks more than the bucket shape or a few extra pounds of ice.
Start with hot tap water. That is enough, and water straight off the stove splashes when the ice goes in, which matters with kids around. Fog is heaviest for the first 5 to 10 minutes and then thins as the water cools, so swap in hot water every 10 to 15 minutes. That matters more than tossing in extra ice. The usual mistake is dumping in more dry ice to fix thin fog when the water had gone cold.
Keep a kettle or a hot tap close by. Pour off some of the cooled water, add hot water, and the fog thickens again without any more ice. Use a plastic or metal bucket, never glass, and leave the lid off.
Nuggets or pellets for fog?
Use 16 mm nuggets. They're bigger than pellets, so they sublimate slower in the bucket and give you a steadier fog over a longer stretch instead of a burst that tails off fast. Pellets work in a pinch but you'll burn through them quicker for the same pound count.
For Halloween setups we sell 16 mm dry ice nuggets by the pound, and for Halloween in 15, 30 and 50 lb packs sized for exactly this kind of job. Check the general writeup on dry ice uses if you're also planning on coolers or drinks for the party, since the same batch can cover more than one job if you plan the pickup right.
Getting the pickup timing right for Halloween
Halloween 2026 falls on a Saturday, October 31. Our regular pickup hours are Monday to Friday, 7 am to 4 pm, so the last regular pickup before Halloween is Friday, October 30.
We also run a Saturday Halloween pickup window just for this: the 15, 30 and 50 lb packs of 16 mm nuggets are available for pickup Saturday, October 31, from 8 am to 12 pm. The Halloween packs are pickup only, with no delivery. You have to order by Friday, October 30 at 2 pm on the shop page to get that slot. Miss that cutoff and the Saturday slot is gone; call 604 239 9333 and we will tell you what we can still do that Friday.
If Friday pickup is your only option, plan for the loss. Dry ice in a cooler with the lid on but not latched loses 5-10 lb per 24 hours (more on how long dry ice lasts in a cooler). Buy a bit heavier than your fog math says, and keep the cooler somewhere cool and out of the sun until Saturday night, lid on but never latched.
A quick example plan
- One bucket, bursts only through a 3-hour trick-or-treat window: start with a 15 lb pack.
- One bucket running nonstop for 2 hours: get the 30 lb pack.
- Two buckets, or a longer haunted garage walkthrough running most of the evening: the 50 lb pack, and top up your hot water often.
Why does fog pool in some spots and not others?
Dry ice fog is heavier than air, so it flows downhill and pools in low spots the way water would. That's exactly the look you want for a graveyard scene on a lawn. It's also exactly why you don't want it building up in an enclosed room.
Outdoors, keep the fog moving: a yard, a driveway, anywhere air circulates naturally. If you're doing a haunted garage, prop the door open and keep air moving through it. A closed basement or sealed garage lets the fog, and the carbon dioxide gas it's made of, build up with nowhere to go, and indoors that becomes a breathing hazard. Full detail on this is on our safety page, worth a read before the big night if you haven't handled dry ice before.
Keeping kids and pets away from the bucket
Dry ice sits at -78.5 °C and causes frostbite-like burns on contact. Gloves or tongs only, every time, no bare hands, not even for "just a second."
Kids are drawn to the fog bucket like it's a prop they're allowed to touch. It isn't. Keep the bucket somewhere guests walk past, not somewhere they can reach into, and keep dry ice out of drinks: a swallowed piece can cause serious burns. If someone does get a burn, or anyone starts having trouble breathing around a closed-up fog area, get medical help.
Pets are worse at reading warning signs than kids are. A dog that wanders over to investigate a smoking bucket doesn't know to stop. If you've got animals in the yard or house during the party, keep the bucket in a spot they can't reach, tucked behind a prop or up on a stand works fine.
Ordering for Halloween
Decide on nonstop fog or bursts, pick your pack size off the numbers above, and book the Saturday Halloween window if Friday doesn't suit your schedule. Order your dry ice online before the Friday 2 pm cutoff and pick your Halloween pack size on the shop page.
Frequently asked questions
How much dry ice do I need for one night of Halloween fog?
It depends on how long you run it. One bucket of hot water running nonstop for 1 hour uses 12-18 lb, for 2 hours 24-36 lb, for 3 hours 36-54 lb. Two buckets double those numbers. If you only run the fog machine in bursts when trick-or-treaters arrive, instead of nonstop, you'll use a lot less than the continuous numbers above.
Should I use hot or warm water for dry ice fog?
Hot water. Hot tap water is enough, and water straight off the stove only splashes. The hotter the water, the more fog, and the fog thins as the water cools, usually after 5 to 10 minutes. Swapping in hot water every 10 to 15 minutes does more for fog thickness than adding extra dry ice. Use a plastic or metal bucket, never glass.
When is the last pickup before Halloween in 2026?
Halloween 2026 is a Saturday, October 31. Our regular Monday to Friday pickup window means the last regular pickup day before Halloween is Friday, October 30. We also run a Halloween-only Saturday pickup, October 31 from 8 am to 12 pm, for 15, 30 and 50 lb packs of 16 mm nuggets, but you must order by Friday at 2 pm on the shop page to get that slot.
Is it safe to run dry ice fog in a garage or basement?
Not if it's closed up. Dry ice fog is heavier than air and flows along the floor, pooling in low spots, which looks great outdoors but is a problem indoors because the carbon dioxide gas can build up with nowhere to go. Keep fog in a yard, driveway, or a room with air moving, prop garage doors open, and never run it in a sealed basement or garage.
Need dry ice? Order online and pick up at our plant in Delta, or have it delivered. Not sure how much? See how much dry ice you need.
