Town had led since the 23rd minute when the excellent Daryl Murphy broke clear down the left and his teasing low centre was turned into his own goal by the unfortunate Richard Wood.
And the in-form home side, who have now gone eight matches without defeat, almost guaranteed the three points after being awarded a second-half penalty.
It was a miss that would prove costly after Jackson's dramatic late leveller.
He said: "It was a tough old game in terrible conditions, but a fair result. The conditions had a big part to play and it took a deflection to beat us.
"But overall they deserved a point. We could have killed it off with the penalty but Didds (McGoldrick) has been brilliant so I can have no recriminations about that."
Unbeaten in eight matches, Ipswich remain in the Championship play-offs and McCarthy added: "We are in the top six on January 1. We could have had two more points but we are in a good position which is testimony to the lads, who have been brilliant."
- Sports & Recreation
- Daryl Murphy