Ontario Parks books 5 months ahead at 7am ET, rolling daily. How to find your booking day, why nothing can be cancelled more than 4 months out, and when sites come back.
Last checked: October 2026. All rules below are from Ontario Parks' own pages as of that date.
The rule: five months, 7am ET
Ontario Parks uses a rolling five-month window. From the reservation rules:
- "Reservations are accepted up to five months in advance of your arrival date." A January 15 booking covers a June 15 arrival.
- New dates open at 7:00am Eastern. Ontario Parks' own blog says that trying before 7am won't let you add the site to your cart, and the call centre starts at 7am too.
- Backcountry, including overnight hiking and interior canoe sites, uses the same five months.
- Daily vehicle permits can be bought up to 5 days ahead, from 7am ET.
There's no single opening day for summer. Every arrival date has its own morning.
How to work out your booking day
Take your arrival date, go back five calendar months, and be ready at 7am ET.
The month-end rule is spelled out by Ontario Parks: July 29, 30 and 31 arrivals all open on March 1, because February has no 29th to 31st. In a leap year, July 29 opens on February 29. 2027 isn't a leap year, so July 29–31, 2027 arrivals all open on Monday, March 1, 2027.
| You want to arrive | Your booking morning (7am ET) |
|---|
| Thursday July 1, 2027 | Monday February 1, 2027 |
| Friday July 16, 2027 | Tuesday February 16, 2027 |
| Thursday July 29 to Saturday July 31, 2027 | Monday March 1, 2027 |
| Sunday August 1, 2027 | Monday March 1, 2027 |
| Friday August 27, 2027 | Saturday March 27, 2027 |
That pile-up on March 1 is real: it's the morning for the last three nights of July and the first of August, all at once.
Stay limits
- Car camping: at some parks the maximum is 7 or 14 nights between July 1 and the Saturday of the Labour Day long weekend. Elsewhere and off-season it's 23 consecutive nights.
- Backcountry: 16 consecutive nights on one site (with exceptions at Killarney), 23 nights across an itinerary.
- Rustic cabins and cottages: 14 consecutive nights.
The 4-month rule
This is the part most people miss. Ontario Parks says: "Reservations cannot be changed or cancelled more than four months in advance of your arrival day."
So if you book on the first possible morning, five months out, you're locked in for about a month. The earliest anyone can give a site back is four months before arrival.
Penalties, and why they push people to cancel early
From Ontario Parks' penalties page, cancelling or shortening a campsite, roofed accommodation or group reservation before noon ET on arrival day costs a percentage of the fees paid, based on how long you've held the reservation:
| Reservation held | Penalty |
|---|
| 1 month or less | 10% |
| More than 1 up to 2 months | 20% |
| More than 2 up to 3 months | 30% |
| More than 3 up to 4 months | 40% |
| More than 4 months | 50% |
- Minimum fee: $7.52 + HST online, $9.29 + HST by phone or in park.
- After noon ET on arrival day: one night's fee plus the percentage.
- The reservation fee itself (about $11 in 2026) and HST aren't refunded.
- Changes cost an administration fee of $7.52 + HST online.
Backcountry uses flat fees instead: from the minimum fee if held a month or less, up to $25 + HST if held more than four months.
What that does to availability
Because the penalty grows the longer you hold a booking, anyone who knows they won't use a site gains by cancelling as soon as they're allowed. Put that together with the four-month lock, and you get two moments when sold-out sites are most likely to come back:
- Right at the four-month mark, when people who booked several options on day one can first drop the extras.
- The last week or so before arrival, when real plans change: weather, illness, a trip that fell through.
That's our reading of the rules. We'll publish opening counts per park once we have a season of data.
Watching a sold-out Ontario park
Canada Camp Alerts watches a few high-demand Ontario Parks areas, including Kilcoursie at Killbear, Riverside Area 1 at Pinery, the Mew Lake yurts at Algonquin and Craigleith Area A. Set a watch on the facility page for your nights. We alert you when a night goes from booked out, or not yet released, to open, meaning any site in that area is free that night. We don't check that one site is free across your stay, and we don't match party size or equipment, so check on Ontario Parks' site before you pay. You book there yourself.
- Free: one watch for one night, email, 15 minutes after pass holders.
- Season pass: C$25 once, 12 months, no auto-renew. Up to 10 watches, date ranges, instant email, Telegram and browser push.
We don't send booking-morning reminders, so put your five-month date in your own calendar.
FAQ
When do Ontario Parks reservations open for summer 2027?
Each arrival date opens five months ahead at 7am ET. For Canada Day 2027 (Thursday July 1) that's Monday February 1, 2027. For July 29 to August 1, it's March 1.
Can I cancel the day after I book?
Not if your arrival is more than four months away. Changes and cancellations are blocked until four months before arrival.
How much does it cost to cancel?
10% to 50% of campsite fees depending on how long you've held the booking, with a minimum of $7.52 + HST online. After noon on arrival day you also lose a night.
Is backcountry different?
Same five-month window, but cancellation penalties are flat fees, up to $25 + HST.
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