Yesterday, July 1st, I took some temperatures in the Spokane River and Hangman Creek.  As you can see in the table below, water temperatures in parts of the Spokane River and Hangman Creek are very hot.  In fact, the Spokane River at Barker Road measured 28.3 C (83 F)!  Hangman Creek measured 26.3 C (79 F).

Location
date
time
air temp (C)
water temp (C)
Water Street
7/1/2015
1500
22.2
16.7
TJ Menach
7/1/2015
1430
27.2
17.7
Hangman at 11th Street Bridge
7/1/2015
1445
21.7
26.3
Barker Road
7/1/2015
1530
24
28.3
Plantes Ferry
7/1/2015
1550
17.3

Today, it was reported that Columbia River temperatures at Bonneville dam are the hottest since 1950.  Air temperatures in this area usually peak at the end of June and the beginning of August.  So the area will endure at least another month of warming waters.  And although people have ways of keeping cool, our aquatic life are stuck with these temperatures.  Trout are stressed at 70 F and begin to die at 80 F, temperatures we are already measuring in part of the river.

As you can see, parts of the river are still very cold.  Downriver from Spokane, water temperatures measure between 16 and 18 C (61 and 64 F).  This is due to the influence of our amazing aquifer, which flows into the Spokane River here.  In the map below, the blue area shows where the aquifer flows into our river, cooling it and also providing a bit of extra flow.  gaining and losing reaches

 

With these temperatures anglers should consider "hoot owl fishing" (early morning) to reduce stress on the native trout they catch and release.