"The farmer in me wants it to rain but the racer in me hopes it will be as hot as hell," he said.
Sinnamon (45) and his brother-in-law, Martin Powley, of Clinton, have again entered the gruelling race as a team, this year competing in the veteran section.
As a Central Otago man, Sinnamon said his advantage over other racers was his experience of scorching temperatures and plentiful sunshine.
"I'm generally from a hotter climate than everyone else and cope with the heat far better than others, which can increase my chances. You don't know who's going to enter or the strength of the field, so to me the hotter the better," he said.
His racing passion developed as a result of a self-confessed lack of rugby talent, which forced him to look elsewhere for exercise and recreation.
A Ghost to Ghost triathlon at St Bathans sparked his interest, and after participating in other Central Otago multisport races, he eventually got hooked on the Coast to Coast.
"One thing led to another," he said.
Sinnamon and Powley have produced some top results over the years, winning the veteran section, placing third, and securing some top-five placings in either veteran or open sections.
"I would like to think we aren't getting any slower . . . and that 45 [years of age] might be my peak. I would like to think we keep them [other competitors] honest," he said.
While rugged rivers, rocky mountains, and vast open landscapes are a highlight of the race for some participants, Sinnamon loves cycling into the relative hustle and bustle of Christchurch.
"To be honest, for a country boy that's as much of a highlight as running through the Southern Alps. When you're coming into town there's all the traffic of Christchurch and police at every intersection ready to stop the traffic and wave you through . . . it's one of the things that makes it what it is," he said.
Sinnamon said his mental approach was to take each race at face value, and agonising over details did not help.
"If you've too many preconceived ideas you come unstuck. Sometimes it comes down to the luck of the draw," he said.
Sinnamon is hoping for rain on his return to Central Otago on February 15.
"If you see a stiff-legged farmer you'll know what's happened," he said.
