Iranians welcomed Tuesday's nuclear agreement as a step toward better fortunes but any revelry appeared to be on hold until Ramadan fasting ends and scorching summer heat eases at sunset.
Authorities in recent days have appeared apprehensive about people taking to the streets to celebrate as they did after a preliminary deal was agreed with world powers on April 2.
Such concern seemed to be heeded as news of a deal in Vienna came through around noon in Tehran, where the temperature hit 39 degrees Celsius (102 Fahrenheit).
And with a few days still left of the Muslim fasting month of Ramadan, it is thought Iranians will celebrate the deal when they later take to the street to eat.
"It's great news because the economy will boom," said Behnam Arian, an accountant, at Argentine Square, a busy commercial district in the capital.
"The negotiations lasted a few years but they will lead to interaction with other countries," he said, echoing remarks by President Hassan Rouhani and Foreign Minister Mohammad Javad Zarif.
"During these talks Mr Zarif represented our country's positions better than his predecessors," he added, alluding to the long-running crisis over the Islamic republic's nuclear programme.
Hamid Bahri, an engineer, appeared relieved the talks were finally over after 18 days of waiting for a breakthrough in Vienna, which was the culmination of almost two years of diplomacy.
"Any deal is better than no deal. There is no bad deal because each side will have benefits and the world powers will secure their interests in Iran in the coming few years," he said.
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The possibility of cooperation between Iran and the West in a conflict-strewn Middle East, typified by Islamic State group jihadists in Iraq, Syria and beyond, also won support.
"Now the terrorist groups will be destroyed gradually," Bahri said.
"When we speak of a political accord, it means that in the future they will definitely talk and cooperate on other issues as well."
Others pointed to the need to try to open up the economy to competition and reverse the fortunes made by so-called "sanctions busters" on the black market that thrived under the nuclear standoff.
"The sanctions were very profitable for some within Iran and thank God their hands will be cut from now on," said Omid Shaterzadeh, a 27-year-old financial sector employee.
Social media also filled up with reaction to the deal.
"Hello world, here's our unclinched hand & open arms, let's give true friendship/peace a chance," a user named Soleil wrote on Twitter, which is filtered by Iranian authorities but accessible via illegal software that circumvents censorship controls.
But the optimism was not universal, as many Iranians doubt whether their chances will brighten because of the nuclear agreement.
"It's a fact that this deal will have no effect on the economic development and daily lives of Iranians," said Abtin Afarinsh, who sells luxury leather goods at Argentine Square.
Shrugging his shoulders, he added: "I'm not going to be fooled by this."