The spike in hash rate this past week has been rapid, from 45 Exahash/s to 62 Exahash/s. This is perhaps indicative of a mining supersite being switched on. A past article on Bitcoin News discussed how mining supersites were being developed for USD 0.5-1 billion by big mining companies like Bitmain, and these supersites would cause an extreme spike in mining hash rate and difficulty that could make small mining operations unprofitable and obsolete. Indeed, mining difficulty is higher than ever at 6.7 trillion, and next time it updates it should be well above 7 trillion. The era of personal Bitcoin mining could be coming to an end quite soon.
Keep in mind that there is no way to know the actual hash rate. The reported hash rate is just an estimate based on the average times between blocks. Since the times are completely random, the reported hash rate will vary quite a bit even when the actual hash rate is constant.
Since short term changes in the reported hash rate are random, it is not reasonable to attribute short term changes to any specific events.