Temperature has dropped through the floor to low 40s this morning, heater on and cup of tea in bed while waiting for the van to warm up. We plan to revisit the Lower, Midway and Upper Geyser Basins today as it's our last full day in Yellowstone. After breakfast we head out only to find the clouds at pretty much ground level and visibility severely limited. We push on to Lower Basin where the springs are shrouded in a mixture of cloud and steam - nothing to see here! Midway Basin is much the same and as we make our way round the Grand Prismatic Spring we can see the bacteria mats at it's outer edge and nothing more, a shame as it's one we were looking forward to seeing. We soldier on towards Upper Basin and a break in the clouds rewards us with enough time to revisit Old Faithful and to walk the entire basin, taking in all of the springs, pools and geysers. The reward is short lived and we end up driving back to Madison Junction in torrential rain. It's dinner in the van tonight and no end to the weather in sight.