US crude exports jumped to their highest level on record in May, coming in at 662,000 b/d, monthly data from the US Energy Information Administration showed.

Exports are up from 591,000 b/d in April and have been up steadily from the 392,000 b/d exported in December, when the US lifted all restrictions on the export of crude oil.

A tight ICE Brent/NYMEX WTI spread through May likely didn’t stand in the way of exports, despite a strong NYMEX discount often making exports more attractive. That spread averaged just 26 cents/b in May, compared with $1.33/b in April.

While exports to Canada — typically the biggest market for US crude — remained strong at 308,000 b/d, that represents under half of the total. In May 2015, Canada took 524,000 b/d of the 531,000 b/d total from the US.

The Netherlands — home to the massive Rotterdam port — imported 110,000 b/d from the US in May, up from 29,000 b/d in April, 20,000 b/d in March and 36,000 b/d in February. While it is unclear which grades make up the export cargoes, S&P Global Platts data shows WTI still delivers into Rotterdam at a sizable premium to Russian Urals and North Sea grades like Forties and Ekofisk.

However, Platts yield data shows WTI should be attractive for European refiners. Light Houston Sweet — essentially WTI ex-Houston — cracking yields in Northwest Europe have averaged $49.23/b since July 1, compared with $48.60/b for Urals and $48.47/b for Forties. Ekofisk has averaged $50/b.

Platts yield data are calculated by applying Platts product price assessments to yield formulas designed by Turner, Mason & Co.

The US also exported 36,000 b/d to the UK, up from 18,000 b/d in April.

Curacao — home to the 335,000 b/d PDVSA-owned Isla refinery — imported 67,000 b/d from the US in May, down from 90,000 b/d in April.

Japan took in 29,000 b/d from the US, up from zero in April but down from 44,000 b/d in March.