"It's always good fun playing in the rain," he jokingly told Sky Sport.
"It evens it out and Southland rolled their sleeves up and we knew we had to turn up and do the same."
Walden said the focus for this week was to have another Monday to prepare for a final.
"We knew we had to turn up. I'm proud of the boys in the first half, we played good but a bit loose in the second, but we got there," he said.
Southland's entry into the play-offs raised eyebrows after only one win of the competition in a Covid disrupted campaign.
Both teams skied high kicks to challenge players under the high ball to force an error.
After beating the same opponents last Sunday, Taranaki stamped their mark early with two tries in the opening 10 minutes.
First, it was Tom Florence who slid through for the first. Referee Jono Bredin checked with video ref Mike Fraser, who awarded the try. Logan Crowley got Taranaki's second with a nice dart through the defence.
The remaining points for Taranaki came off the boot of leading competition points scorer Stephen Perofeta, who slotted five penalties in his 50th match. Taranaki led 16-6 at the break.
Taranaki had plenty of chances to score if it wasn't for knock-ons at lineout time close to the line or not straights.
Replacement halfback Liam Blyde was denied a try after a knock-on before the line. In one of the most attractive plays in the game with minutes remaining, Kini Naholo made a burst down his wing only for the inside pass to be knocked on. It was referred to Fraser again.
Southland were keen to run the ball out of their own 22 but had a lack of penetration, despite Rory van Vugt scored after another TMO check and Marty Banks claimed the Stags' second. Banks kicked a conversion and two penalties.
Taranaki 25 (Tom Florence, Logan Crowley tries; Stephen Perofeta 5 pen)
Southland 13 (Rory van Vugt try; Marty Banks con, 2 pen).
HT: 16-6
