The Coast Mountains to the west of the region tend to protect the Cariboo Region from coastal rainfall, creating a drier continental four-season climate with summer months temperatures averaging between 60 - 70 degrees Fahrenheit during daytime hours. However, this is mountain country and thunder storms can develop in the afternoons and drench the countryside. For the most part, expect crisp mornings, partially cloudy to bright mountain-sunny days and cool nights. Anglers should dress in layers and have their raingear handy at all times ready to adjust to varying weather conditions.
The answer to the question about the best time to visit the Blackwater is - anytime from the middle of June through the end of September! The fly fishing is consistent throughout the season and each day outfitter, Dave Harrington, chooses several different float trip options depending on the water conditions.
At the season opening, in mid-June, the days are at their longest with daylight from four in the morning to nearly eleven at night, allowing lots of time to enjoy the outdoors and long hours for fish to feed. Although the early season offers somewhat higher water levels, making wading possibilities a bit more limited, it is a prime time to fish the Blackwater. This is probably the heaviest feeding period of the year with prolific stonefly, caddis and occasional mayfly hatches, as well. Keep in mind, the weather can still be variable with occasional cool days and afternoon thundershowers. There will likely be a few mosquitoes around camps and lunch stops, but they are generally not a great problem, unless the previous few weeks have been abnormally wet.
Whatever your seasonal preferences are, or your schedule allows, the Blackwater provides a great combination of excellent fly fishing, wonderful hospitality all in a true wilderness setting.
In July, the days shorten slightly and the weather tends to become warmer and drier with occasional thundershowers, and water temperatures in the 60 to 65 degree range. Caddis and stonefly hatches are still heavy, and most fishing is with large yellow and orange dry patterns. Near the middle of July, in most summers, the river levels continue to drop and water temperatures increase to around 65 degrees, becoming very nice for wet wading and the odd dip. Caddis and mayflies are active on the water. The day length is now about 5AM to 10PM (a little more darkness for sleeping).
By the first of August, the water will be near its warmest and can even be over 70 degrees Fahrenheit. This is generally the time period when, on warm years, the fish can become a bit temperamental. The next week or so can often be the most difficult fishing, but we have found ways to improve success over the years. This is also the most comfortable time of the year on the Blackwater, with warm, clear days.
Mid August, typically, marks the point when the water and the weather begin to cool down. The days are a little shorter, getting light at about six in the morning and turning dark at about nine at night. The good news is the mosquitoes are virtually non-existent, and the trout are just as hungry as ever! The fish are feeding more actively again with the drop in water temperature, and readily attack large attractor patterns. They also seem to show a lot more size. Typically, this part of the season is "lower Blackwater time", which translates into the fish being even more heavily concentrated in amazing pieces of water that were otherwise inaccessible, or not conducive to dry fly fishing under higher water conditions.
In September, the days become even shorter with daylight hours from 6:30 a.m. to 8 p.m. Dry flies still do well and this is also a great time for nymphs and streamers. The Blackwater usually experiences stable weather in the fall, and as the nights grow longer, frost becomes more frequent. By mid-month fall colors are abundant. Wet wading is over!
So there you have it - anytime is a great time to fish the Blackwater. You'll experience gradual changes from the long, warm early summer days, to fall colors and starry nights. The Blackwater weather is moderate due to its location in the central Fraser Plateau, in the lee of the coastal mountains, which take the steam out of any Pacific weather system.