Nick Levine of Digital Spy Blog gave the song a positive review stating:
With his last two singles stalling outside the UK top 20, his Third Strike album yet to threaten the UK top 40, and the Brits panel forgetting conveniently that he exists, it's hard to avoid the conclusion that pretty much every clap of his grime-pop crossover thunder has been stolen by another fashion-conscious MC from our fair capital whose semi-comic nom de plume begins with "T".
This latest album spin-off is likely to help him grab it back. Stryder's Made-it-through-against-the-odds rhymes are as earnest as ever, and Canadian soul belter Melanie Fiona turns in a fairly mighty vocal, but, as midtempo electro-R&B tunes go, 'Let It Rain' is a bit like a family saloon that's due its MOT: perfectly serviceable but not terribly exciting. Not half as exciting, it has be said, as a similarly-themed recent offering from a certain Mr Tin... .
"Let It Rain" debuted on the UK Singles Chart at number 103 on 9 January 2011. The following week, the single rocketed up the UK Singles Chart, jumping 65 places to number 38; marking Stryder's ninth UK Top 40 hit and fourth consecutive UK Top 40 single to have been released from Third Strike. On 23 January 2011, the single climbed a further 12 places to number 25 on the UK Singles Chart. On 30 January 2011, the single climbed a further 11 places to number 14 on the UK Singles Chart.