The current difficulty is 1,162 PH. The next difficulty is estimated at 1,167 PH, a change of +0.40%. The difficulty changes globally every time a new block is mined, based on how fast blocks are being found.
Hash Price Report
The last block was at height 20,636. The current block reward is 223,490.4 SCP. Based on this and on the current difficulty, miners are being paid 186.5070 SCP/PH, which corresponds to about 16.11 SCP/day per GH/s.