By and large dictionaries have a correct IPA transcription but they often make the same mistakes with the same three sounds:
1. The ‘a' sound is transcribed as the open front [a] but actually the standard Parisian pronunciation is the near-open central [ɐ]. It may be different in other regions or in other French speaking countries.
2. The nasal ‘o' is often transcribed as the open-mid round [ɔ̃] but actually it’s more a mid-back rounded [ɔ̝̃].
3. The ‘r’ sound is sometimes transcribed as the the uvular trill [ʀ] which is definitely a mistake since nobody uses that sound (except from Edith Piaf in her songs). I’d say that about 70-80% of the time the standard pronunciation of ‘r’ is the voiced uvular approximant [ʁ̞]. In complex onsets (that is in ‘tr', ‘dr', ‘br', ‘pr’, ‘vr’, ‘fr' sequences at the beginning of a syllable) we tend to use the voiced or voiceless uvular fricative [ʁ]/[χ].
Any modern French dictionary.
bonjour | bɔ̃ʒuʀ | aujourd'hui | oʒuʀdɥi |