Farmers are "playing roulette" after a dry winter with crops "crying out for rain".
And although the crops are "looking good" there is no water underneath them, according to southern Riverina agronomist Tim Paramore.
"What we seem to have is the crops look quite good but we need rain," he said.
"Farmers are really playing roulette at the moment and the next few weeks could make or break us.
"Henty Machinery Field Days is usually D-day for us."
Mr Paramore, who is based in Walla said the problem was there hasn't been a big rain event since May.
"We have had about 225 millimetres of rain this winter," he said.
"But we haven't had a proper downpour for months.
"If we could get another 50 millimetres to fall it would put us in the game.
"Some people are spraying their canola this time of year and that can be expensive as you have to be sure you are going to get results."
Mr Paramore said some farmers are opting to cut crops for hay to help them get through the summer.
"People are thinking about making hay or silage and enough to get their stock through," he said.
"It is looking quite serious if that process continues this way.
"You can feel it warming up and that is when people start to panic when the heat comes in with wilting points."
Pleasant Hills farmer Rick Clancy said cutting crops for hay is "unheard of" in the area.
"But some of us are choosing to do it because of the potential yield loss if we don't get any more rain," he said.
"If we get rainfall the crops could still bounce back.
"I would say we are right on the cusp at this stage - the next week could really determine how our harvest will go."
Mr Clancy, who farms with his mother Brenda, brothers Hugh and Gerard, sister-in-law Virginia, wife Julianne and son Thomas, said at this stage they are looking to harvest crops "not cut crops".
"It's not critical at the moment but we definitely need a good soaking," he said.
"We have canola, wheat and barley and the heat this week looks like determining how the crops will continue.
"It is a really hard one at the moment to predict our yields because the crops still have a lot of potential but there are so many different variants we have to compete with. The frosts have been brutal, a bloke I was talking to the other day reckons he has had 18 in August."
Mr Clancy said a good winter he would receive at least 300 millimetres of rain.
"But we have only had 225 millimetres," he said.
"The last big rain was 15 millimetres on July 8 so we really haven't had a decent rain for more than a month.
"A good 50 millimetres would be ideal but the next few weeks will tell us more."
The Bureau of Metereology predicts the Border to have a top of 21 degrees on Tuesday with Wednesday and Thursday expecting a top of 19 and 18 respectively.
"There is meant to be a sprinkling of rain later in the week but if we get six or seven millimetres that would be alright but we need it to continue," Mr Clancy said.