* Gold down 4.2% so far this month
* Dollar on track for best month since July 2019
* Interactive graphic tracking global spread of coronavirus: https://graphics.reuters.com/world-coronavirus-tracker-and-maps/ (Updates prices)
By Eileen Soreng
Sept 30 (Reuters) - Gold was set for its biggest monthly decline in nearly four years, led lower on Wednesday by a stronger dollar as caution returned to markets after the first U.S. presidential debate.
Spot gold XAU= fell 0.6% to $1,886.78 per ounce by 0812 GMT, declining 4.2% so far in the month in what would be its worst monthly performance since November 2016.
U.S. gold futures GCv1 were down 0.5% at $1,893.40.
The dollar index .DXY was up 0.1%, en route to its biggest monthly gain since July 2019, making gold more expensive for holders of other currencies. USD/
"The dollar's post-debate gains foiled gold's latest attempt to hit the psychologically important $1,900 handle," said FXTM market analyst Han Tan, adding that the currency was investors' favoured safe-haven asset now.
But he said, "should investors grow more concerned over the prospects of a delayed outcome to the elections, the extended political uncertainty could offer the metal another leg up over the coming weeks."
The debate in Cleveland turned chaotic as President Donald Trump and Democratic rival Joe Biden battled fiercely over Trump's record on the COVID-19 pandemic, healthcare and the economy. bought gold to hedge risk ahead of the presidential debate. Now that it has passed without incident, those hedges are being unwound," said Jeffrey Halley, a senior market analyst at OANDA.
Also taking some shine off gold was upbeat Chinese data on manufacturing and services activity as market participants tracked progress on a new U.S. coronavirus relief bill. has entered into a temporary consolidation phase but this may be a short-term correction in a long-term bull run, as we move towards a second U.S. fiscal stimulus," said Margaret Yang, a strategist with DailyFx, which covers currency, commodity and index trading.
Silver XAG= fell 1.5% to $23.81 per ounce, platinum XPT= was down 1.6% at $870.36 and palladium XPD= was up 0.1% at$2,311.71.