Slough rates AS the country prepares for a gradual easing of lockdown restrictions, we have rounded up the latest case numbers to show how cases and rates are currently looking in Slough. A spread of different colours a few months ago, the Government's Covid-19 map showed almost the whole of Slough as a sea of purple and dark purple in recent weeks, indicating that the rolling rate for each postcode was above 400 or 800 respectively. But now some locations are once again showing as light blue, indicating a lower rate of 200 or less.