Key Aspects:
- Seasonal flooding from Suicide Basin near Mendenhall Glacier in Juneau, Alaska is expected in early to mid-August 2026.
- While the extent of any flooding cannot be predicted, cruise shore tours will likely be impacted for several days.
- No cruise lines are adjusting any itineraries to Juneau at this time and visits are unlikely to be cancelled.
It’s that time of year again, when Suicide Basin at Mendenhall Glacier is seeing rising water levels and the seasonal overflow that can cause significant flooding in and around Juneau, Alaska, one of the most popular cruise destinations in the Last Frontier.
The National Weather Service is closely monitoring the basin’s water levels, particularly since the August 2025 flooding reached record levels.
Suicide Basin is a side basin just east of Mendenhall Glacier. Once the basin fills with rain and the snow melts, the water breaks out under the glacier and can flood several miles of the valley below.
Mother Nature can be unpredictable, but the basin is expected to reach capacity sometime from August 8-12, 2026.
“Cloudy days will push the timing beyond that range while more sunny days would push it to the beginning of that range,” the NWS carefully notes.
Furthermore, just because the basin reaches its fill limit, that does not mean flooding will begin immediately.
“In the past it has taken up to 6 days for the main event (sub-glacier release) to start after the basin is full with water going over the overflow channel,” the NWS said.
There is no easy way to predict the extent of flooding or any closures or damage that may occur. Nevertheless, local authorities are staying alert to the situation and will take all necessary precautions to safeguard the region.
In mid-August, dozens of cruise ships are scheduled to visit Juneau, including vessels from Carnival Cruise Line, Princess Cruises, Holland America Line, Norwegian Cruise Line, Disney Cruise Line, Royal Caribbean, Oceania Cruises, Celebrity Cruises, MSC Cruises, and more.
The cruise docks in Juneau are approximately 10 miles southeast of Suicide Basin and Mendenhall Glacier, and are therefore not at risk from floodwaters.
How Will Cruises Be Impacted?
While no cruise lines are thus far shifting itineraries away from Juneau, it is likely that shore tours may be impacted when the flooding occurs.
This can include hikes, kayaking, and glacier viewing changes or cancellations. Booked guests should be aware of the situation and adjust their expectations accordingly. Similarly, guests planning to explore Juneau independently should stay alert to the conditions that may impact their visit.
According to the City and Borough of Juneau, peak flooding is typically 24-48 hours after the Suicide Basin begins to release. It can be several days, however, before the waters recede. After that, inspections for debris and damage must be conducted before regular visits and tours may resume.
Tours away from the flood area are not usually impacted and will likely move forward as scheduled.
Guests who have booked tours in Juneau during August should stay in close contact with their tour operator (or the cruise line, if booked through the line) to be notified of changes or cancellations. Tour operators are local businesses and will have the most up-to-date information for each guest’s visit and excursion plans.
Depending on the extent of any flooding this year, cruise lines may donate for recovery efforts. Following the catastrophic flooding in August 2024, Norwegian Cruise Line Holdings donated $50,000 for community recovery.
Cruise lines are well known for supporting the communities they visit and often arrange charitable projects in addition to the economic support their visits bring to the region.
