MetService said after heavy rain fell on Monday more rain was predicted tomorrow when "similar or greater impacts of rainfall can be expected".
However, Emergency Management Otago (EMO) advised rainfall of "biblical proportions" would be required for Lake Wānaka to flood.
Lake Bar owner Pete Byrne said his lakefront business had been issued a reminder about the rising levels.
His first reminder came from building management last month and, since then, the lake has fluctuated a few hundred millimetres either way.
"As a business we’re waiting for the lake levels to reach 279.2m above sea level before we start taking action," he said.
"However, we are taking early precautions.
"We’re not in panic mode just yet. We’ve been through it before as a business and building six years ago, so we have plans in place."
If lake levels did rise, Mr Byrne said the the next steps would be moving things out of the basement and lower level of the restaurant, "which takes manpower more than anything".
Otago Regional Council data shows lake levels reached 278.58m above sea level yesterday morning.
The last time Lake Wānaka experienced flooding was in December 2019, when lake levels reached 280.3m.
MetService said this month had already produced 30mm more rain than the usual monthly average.
Yesterday morning MetService meteorologist Mmathapelo Makgabutlane said that this month had produced 88.2mm of rainfall compared to the average of 51mm.
At the start of the week MetService reported 24.4mm of rainfall on Monday morning alone.
The weather forecaster predicted heavy rain until 3am yesterday and an active front moving up the South Island.
Yesterday, MetService issued an orange heavy rain watch for the headwaters of the Otago lakes and rivers from midnight tonight to 2pm tomorrow.
However, EMO emergency adviser Craig Gibson said rainfall would have to be of "biblical proportions" to warrant any panic about flooding at the lakefront.
A first alarm would be issued if lake levels reached 279.2m and the emergency service had an around-the-clock on-call duty officer that monitored these situations, Mr Gibson said.
He said the service worked closely with Earth Sciences New Zealand in order to predict weather patterns.
"What we have to look at really is the forecast.
"We can’t be too flippant because it is a fine balance between message fatigue and so the alerts have to stay relevant."
All messages or alerts were evidence-based, but in an emergency situation, there had to be some "feeling"-based decisions made ahead of time.
"We have to balance that without being alarmist. It is a good reminder to the public that this is spring weather.
Mr Gibson was not worried about the snow levels on the hilltops compared to recent years in spring.
He was closely monitoring the lake levels in the Wānaka catchment including Matukituki, Lindis, Wilkin and Cardrona rivers.
"While river and lake levels are expected to rise significantly as a result of the heavy rain forecasted, Lake Wānaka levels are not expected to reach first alarm [awareness] level, and little lakeside effects are expected."
A Queenstown Lakes District Council spokesman said the council was working closely with EMO and the Otago Regional Council and took advice when it came to lake levels.
"Residents and businesses should not be worried and do not need to take any particular precautions," the spokesman said.
"Should the situation change — which we do not expect during this particular weather cycle — then QLDC will certainly let the community know in good time via our usual channels."
