Premise[]
If this gets posted then it means it got a result higher than High 8-C, woo.
Basically, this spell can freeze a fairly decent chunk of water. When you first get it, it will instantly freeze 1100 sq ft of water up to 6 inches deep. In theory you could double this by having the sphere hit two water body sources but let's not get ahead of ourselves.
Calc[]
The volume of the above would be 15.574 m^3 of water, frozen instantly, which leads me to assume standard -40 C temp for nigh-on instant freezing.
Density of Water = 997 kg/m^3
Mass of Water = 15527.278 kg
Temperature Change = 25 C -> -40 C = 65 C (This can work in any environment, including exceedingly warm ones)
Specific Heat of Water = 4181.3 J/(kg*K)
From heat change we get 4.220e9 Joules, but we ain't done there. Now for the freezing bit. Latent heat of fusion for water is 334000 J/kg. So uh. This comes out to 5.186e9 Joules. Meaning we exist in High 8-C but only barely. So this isn't relevant. Rip.
Tallies[]
Freezing Sphere Freezes: 2.25 Tons of TNT, Large Building level