Best Time for a 1000 Islands Cruise: Season, Weather & Fall Color

The 1000 Islands cruise season month by month

If the cruise is one part of a wider Kingston or Thousand Islands trip, June to September is also the warmest time for the rest of it; in winter there are no cruises on the river at all. The notes below say what each part of the season is like on the water. Dates are the operators’ 2026 ones unless a year is given.

Mid-April to early May: the first sailings

Kingston 1000 Islands Cruises starts in mid-April (April 18 in 2026) with a small program, partly weather-dependent: the 3-hour lunch cruise every day at 12:30 p.m., the 3-hour Heart of the Islands sightseeing cruise at 12:30 p.m. and a 1-hour harbor cruise at 4 p.m. Rockport’s 1-hour cruise starts on May 1, and in 2025 City Cruises expected to open its Ivy Lea port around April 18. Boldt Castle stays closed until early May. The trees are only starting to leaf out: the last spring frost is usually in late April, and Kingston’s average high is 10.0°C (50°F) in April.

Early May to June: most of the season opens

Most of the season opens together in early May. Boldt Castle opens on May 9 in 2026, so the Boldt Castle stopover cruises from Gananoque and Rockport can run, and Kingston moves to its spring schedule with the sunset dinner cruise on Friday to Sunday evenings and three harbor cruises a day. Victoria Day weekend (May 16 to 18 in 2026) is one of the Kingston operator’s busiest weekends. Average highs in Kingston are 17.6°C (64°F) in May and 22.1°C (72°F) in June, and in mid-June the sun sets at about 8:50 p.m., so a 6:30 p.m. dinner cruise watches the sunset from the river.

Late June to August: the widest choice

From late June (June 27 in 2026) Kingston’s summer timetable adds a second daily sightseeing departure, a dinner cruise every evening and summer-only cruises. Ontario schools finish in late June, and Canada Day (July 1), the Fourth of July, the Civic Holiday weekend and every Saturday in July and August are on the Kingston operator’s list of its busiest days. Average highs are 25.4°C (78°F) in July and 24.6°C (76°F) in August, and Kingston averages about 17 days in July and 15 in August with a humidex of 30 or more, against about 5 in June or September. Thunderstorms are most frequent in July and August, on about 3 days a month in Environment Canada’s normals for Kingston. From August 19 the dinner cruise leaves at 5:30 p.m. instead of 6:30 p.m., because the sun sets earlier.

September: most cruises, fewer people

After Labour Day (September 7 in 2026) the summer-only cruises stop and Kingston’s sightseeing cruise drops back to one departure a day, but almost everything else keeps running until mid-October, including Boldt Castle and the Friday-to-Sunday dinner cruise. Kingston’s average high is 20.5°C (69°F), the sun sets at about 7:20 p.m. in mid-September, and the trees can still be quite green in mid-September; the first color usually shows late in the month. September has the highest rainfall total of the cruise season (about 95 mm at Kingston) but no more wet days than June.

October: fall color and the end of the season

October is the fall-color month on the river, and the end of the main season. Boldt Castle closes after Thanksgiving Monday (October 12 in 2026), and the Boldt Castle stopovers and Kingston’s dinner cruise end with it. After that Kingston runs its lunch cruise, a weather-dependent sightseeing cruise and a 1-hour harbor cruise until November 1, City Cruises sails from Gananoque until October 31 and from Ivy Lea into the first days of November, and Rockport’s 1-hour cruise runs until October 31. Kingston’s average high falls to 13.8°C (57°F), it is windier on the water than in summer, and the sun sets at about 6:25 p.m. in mid-October.

November to mid-April: no regular cruises

The last cruises of 2026 are on November 1 from Kingston and November 3 from Ivy Lea, and regular sightseeing cruises stop for the winter. Average highs in Kingston are 7.5°C (46°F) in November and −2.6°C (27°F) in January, with snow from November to April. The operators publish the next season’s dates during the winter; in 2026 the first Kingston sailings were on April 18.

Rain and snow is the average total for the whole month, with snow counted as its melted water, and the number of days with at least 0.2 mm; it says nothing about how long it rained on any day. The temperatures are averages for Kingston, not a promise about your day, and on the open river it feels cooler than in town.

Which cruise suits your month

From May to mid-October most cruises are running, and the Gananoque cruise is the most-reviewed on this site: the 1000 Islands cruise from Gananoque comes in 1-, 3- and 5-hour versions, rated 4.5 out of 5 from 5,683 reviews. The 3-hour cruise passes Boldt Castle and Millionaires’ Row, and the 5-hour one stops at the castle, which needs a passport and runs only while the castle is open. Our full breakdown →

If you are staying in Kingston, the Heart of the Thousand Islands cruise spends three hours among the wooded Admiralty Islands, rated 4.3 from 1,057 reviews, and runs from mid-April to November 1. For a meal on the water, the lunch cruise sails every day of the Kingston season (rated 4.5 from 333 reviews), and the sunset dinner cruise (rated 4.5 from 310 reviews) sails every evening from late June to August and on Friday to Sunday evenings in May, June, September and early October. Kingston dinner cruises compared →

For a shorter trip, the Ivy Lea cruise (1 or 2 hours, rated 4.6 from 1,477 reviews) and the Rockport cruise (rated 4.7 from 100 reviews) both show Boldt Castle from the water and keep sailing to the end of October, with Ivy Lea into the first days of November. That makes them the easiest choice after Thanksgiving, when the castle and the longer cruises have finished.

Boldt Castle stopovers: dates, hours and passports

Boldt Castle on Heart Island is open from May 9 to October 12 in 2026, from 10:30 a.m. to 6:30 p.m., with the admissions booth closing an hour earlier and later hours on July 3 and 4. The stopover cruises from Gananoque and Rockport run only in that window, and Rockport’s sails on select dates from May 10, so check its calendar for your day. The castle is an official US port of entry, staffed from 10:30 a.m. to 5:30 p.m., so landing there means formally entering the United States, and the documents are set by your cruise operator. Rockport, for example, requires a valid passport or NEXUS card, does not accept permanent resident cards, and asks visitors of other nationalities to arrange any visa, ESTA travel authorization or I-94 arrival record at least 72 hours before the cruise; the documents are checked at the ticket office before you board. City Cruises likewise asks for a passport or NEXUS card and, for visitors from outside Canada and the US, a visa or ESTA. Your time on the island depends on how long customs takes. The castle itself has no heating or air conditioning, so dress for the day. Do you need a passport for Boldt Castle? →

Seeing Boldt Castle is not the same as stopping there. The cruises that pass the castle without landing, such as the 3-hour cruise from Gananoque and the 1-hour cruises from Ivy Lea and Rockport, need no passport: Rockport says passports are not required for any of its non-stop cruises. These cruises also keep running after the castle closes.

When is the fall color on the river?

The best color on the river usually comes from late September to mid-October, and the timing moves from year to year. South Eastern Ontario’s tourism board gives a wider window, from mid-September, and the Thousand Islands tourism council describes the river reflecting the reds, oranges and yellows back at the islands in September and October. In 2025, New York State’s foliage report had the trees at the Thousand Islands Bridge half turned in the last week of September and at their peak in the third week of October; in late September 2026 they were only starting to turn.

That timing has a catch: the later color arrives after Boldt Castle, the stopover cruises and Kingston’s dinner cruise have finished (October 12 in 2026). From Thanksgiving to the end of October the Gananoque, Ivy Lea and Rockport sightseeing cruises and Kingston’s lunch cruise still sail. Check the New York State foliage report or Ontario Parks’ fall color report in the week before you go. Which cruise to take for fall color →

Weather on the water

The boats of all three operators we checked have indoor decks as well as open upper decks, so rain changes where you sit more than whether you go. Kingston 1000 Islands Cruises sails rain or shine unless a captain decides it is unsafe, and Rockport says its boats have enclosed areas for rainy days, although a cruise is occasionally cancelled or delayed for bad weather. If the operator cancels, Kingston offers a new date or a full refund.

Wind makes the biggest difference to how the trip feels. It is usually windier on the open river than in town, and at Kingston the average wind is lowest from June to August and highest from October to January. The river forecast is Environment Canada’s Kingston to Cornwall marine forecast. In July and August the risk is heat and thunderstorms: humid afternoons are common, and thunderstorms come on about 3 days a month, so on a hot day the indoor deck is the cooler seat; the Island Star, which carries many of Kingston’s dining cruises, has an air-conditioned cabin.

For packing, Kingston averages highs of about 25°C (77°F) in July and 14°C (57°F) in October, and the deck feels colder than either figure once the boat is moving.

How busy do the cruises get?

July and August are the busiest months. The Kingston operator says many departures sell out days or weeks ahead, especially on holiday weekends, and its list of busiest days for 2026 is every Saturday in July and August plus the Victoria Day, Canada Day, Fourth of July, Civic Holiday, Labour Day and Thanksgiving weekends. Rockport and City Cruises also recommend booking ahead in summer, and parking at Gananoque and Ivy Lea can be limited at peak times.

None of the three operators we checked publishes passenger numbers by month, so the best guide to how busy the region gets is the count of travelers crossing the border at the Thousand Islands Bridge, next to Ivy Lea. In 2025 it was about 135,000 in July and 146,000 in August, against about 89,000 in each of May, September and October; 2024 showed the same pattern at higher levels. The count includes Canadians coming home as well as visitors, and it says nothing about how full a particular boat will be.

Frequently asked questions

Sources and methodology