Oil Prices in May 1991: WTI & Brent Daily Prices and Monthly Average
WTI averaged $21.23 per barrel in May 1991, up $0.40 (1.9%) from April 1991. A year earlier, in May 1990, it averaged $18.20, so the price was higher by $3.03 (16.6%) year over year.
Daily spot prices, May 1991
Chart data table (22 rows; WTI on 22, Brent on 22)
| Period | WTI | Brent |
|---|---|---|
| May 31, 1991 | $21.16 | $19.00 |
| May 30, 1991 | $21.30 | $18.73 |
| May 29, 1991 | $21.04 | $18.75 |
| May 28, 1991 | $21.34 | $19.00 |
| May 24, 1991 | $21.04 | $18.83 |
| May 23, 1991 | $20.95 | $18.78 |
| May 22, 1991 | $20.85 | $18.58 |
| May 21, 1991 | $20.95 | $19.03 |
| May 20, 1991 | $21.39 | $18.90 |
| May 17, 1991 | $21.19 | $18.75 |
| May 16, 1991 | $20.91 | $18.75 |
| May 15, 1991 | $21.04 | $18.80 |
| May 14, 1991 | $20.73 | $18.95 |
| May 13, 1991 | $20.89 | $19.25 |
| May 10, 1991 | $21.25 | $19.53 |
| May 9, 1991 | $21.92 | $20.08 |
| May 8, 1991 | $21.83 | $19.80 |
| May 7, 1991 | $21.72 | $19.85 |
| May 6, 1991 | $21.73 | $19.80 |
| May 3, 1991 | $21.43 | $19.55 |
| May 2, 1991 | $21.17 | $19.70 |
| May 1, 1991 | $21.28 | $19.70 |
Prices peaked at $21.92 on May 9, 1991, then fell to $20.73 on May 14, 1991 and ended at $21.16.
Brent averaged $19.19, on matched dates $2.05 below WTI on average across 22 dates.
Among the 41 May averages EIA has published, 1991's ranks 14th lowest. Within 1991 it ranks 6th lowest of the 12 monthly averages. In October 2026 dollars (CPI-U), the average equals $52.84 and the high of $21.92 equals $54.56.
May 1991 summary
| Measure | WTI | Brent |
|---|---|---|
| Monthly average | $21.23 | $19.19 |
| Change vs April 1991 | +$0.40 | +$0.01 |
| Change vs May 1990 | +$3.03 | +$2.84 |
| Highest daily price | $21.92 May 9, 1991 | $20.08 May 9, 1991 |
| Lowest daily price | $20.73 May 14, 1991 | $18.58 May 22, 1991 |
| Published daily observations | 22 | 22 |
| Average in October 2026 dollars (CPI-U) | $52.84 | $47.76 |
Monthly averages are EIA's published figures. Real figures use CPI-U for May 1991.
May in other years
| Year | WTI average | vs May 1991 | Real |
|---|---|---|---|
| 2026 | $102.13 | +381.1% | $102.86 |
| 2025 | $62.17 | +192.8% | $65.27 |
| 2024 | $80.02 | +276.9% | $85.99 |
| 2023 | $71.58 | +237.2% | $79.44 |
| 2022 | $109.55 | +416.0% | $126.50 |
| 2021 | $65.17 | +207.0% | $81.71 |
| 2020 | $28.56 | +34.5% | $37.60 |
| 2019 | $60.83 | +186.5% | $80.17 |
| 2018 | $69.98 | +229.6% | $93.88 |
| 2017 | $48.48 | +128.4% | $66.86 |
| 2016 | $46.71 | +120.0% | $65.63 |
| 2015 | $59.27 | +179.2% | $84.12 |
| 2014 | $102.18 | +381.3% | $144.96 |
| 2013 | $94.51 | +345.2% | $136.93 |
| 2012 | $94.66 | +345.9% | $139.02 |
| 2011 | $100.90 | +375.3% | $150.71 |
| 2010 | $73.74 | +247.3% | $114.07 |
| 2009 | $59.03 | +178.0% | $93.16 |
| 2008 | $125.40 | +490.7% | $195.37 |
| 2007 | $63.46 | +198.9% | $103.00 |
| 2006 | $70.84 | +233.7% | $118.07 |
| 2005 | $49.83 | +134.7% | $86.51 |
| 2004 | $40.28 | +89.7% | $71.89 |
| 2003 | $28.11 | +32.4% | $51.70 |
| 2002 | $27.04 | +27.4% | $50.76 |
| 2001 | $28.63 | +34.9% | $54.38 |
| 2000 | $28.79 | +35.6% | $56.66 |
| 1999 | $17.72 | −16.5% | $35.98 |
| 1998 | $14.91 | −29.8% | $30.91 |
| 1997 | $20.82 | −1.9% | $43.89 |
| 1996 | $21.17 | −0.3% | $45.63 |
| 1995 | $19.74 | −7.0% | $43.77 |
| 1994 | $17.89 | −15.7% | $40.94 |
| 1993 | $19.95 | −6.0% | $46.69 |
| 1992 | $20.98 | −1.2% | $50.69 |
| 1991 | $21.23 | — | $52.84 |
| 1990 | $18.20 | −14.3% | $47.54 |
| 1989 | $20.12 | −5.2% | $54.85 |
| 1988 | $17.42 | −17.9% | $50.04 |
| 1987 | $19.44 | −8.4% | $58.01 |
| 1986 | $15.38 | −27.6% | $47.67 |
“—” in the real column means BLS has published no CPI-U for that month. The comparison column shows how far that year's average was from May 1991.
Source and methodology
| Provider | Series | Units | Coverage | Latest observation |
|---|---|---|---|---|
| U.S. Energy Information Administration | RWTC — WTI spot price FOB (daily, monthly) | $/bbl | May 1, 1991 – May 31, 1991 | May 31, 1991 |
| U.S. Energy Information Administration | RBRTE — Brent spot price FOB (daily, monthly) | $/bbl | May 1, 1991 – May 31, 1991 | May 31, 1991 |
| U.S. Bureau of Labor Statistics | CUUR0000SA0 — CPI-U, all items, NSA | index, 1982–84=100 | monthly | October 2026 |
Last updated: Nov 10, 2026, 7:01 PM CST. Raw values are shown in source units; any conversion is labeled. See methodology and data sources.
Download:1991 daily prices (CSV)